Final Report : Automated Speed Enforcement Pilot Project for the Capital Beltway: Feasibility of Photo-Radar
Click HERE for graphic.
Click HERE for graphic.
FINAL REPORT
AUTOMATED SPEED ENFORCEMENT PILOT PROJECT
FOR THE CAPITAL BELTWAY:
FEASIBILITY OF PHOTO-RADAR
Cheryl W. Lynn ROBYN LAU
Senior Research Scientist Graduate Legal Assistant
Nicholas J. Garber JANICE V. ALCEE
Faculty Research Engineer Graduate Legal Assistant
Wayne S. Ferguson JONATHAN C. BLACK
Senior Research Scientist Graduate Legal Assistant
Torsten K. Lienau PETER M. WENDZEL
Research Assistant Graduate Legal Assistant
(The opinions, findings, and conclusions expressed in this
report are those of the authors and not necessarily
those of the sponsoring agencies.)
Virginia Transportation Research Council
(A Cooperative Organization Sponsored Jointly by the
Virginia Department of Transportation and
the University of Virginia)
Charlottesville, Virginia
November 1992
VTRC 93-R6
SAFETY RESEARCH ADVISORY COMMITTEE
W.H. LEIGHTY, Chairman, Deputy Commissioner, Department of
Motor Vehicles
J.D. JERNIGAN, Executive Secretary, Senior Research Scientist,
VTRC
J.L. BLAND, Chief Engineer, Department of Aviation
R.J. BREITENBACH, Director, Transportation Safety Training
Center, Virginia Commonwealth University
MAJ. J.K. COOEE, Assistant Chief of Law Enforcement,
Department of Game and Inland Fisheries
M.L. EDWARDS, Executive Assistant, Office of the Secretary of
Transportation
W.S. FELTON, JR., Administrative Coordinator, Commonwealth's
Attorneys'Services and Training Council
R D. FERRARA, Ph.D., Director, Division of Forensic Sciences,
Department of General Services
D.R. GEHR, Assistant Commissioner-Operations, VDOT
LT. COL. C.M. ROBINSON, Director, Bureau of Field Operations,
Department of State Police
J.T. HANNA, Assistant Professor, Transportation Safety
Training Center, Virginia Commonwealth University
T.A. JENNINGS, Safety/Technology Transfer Coordinator, Federal
Highway Administration
B.G. JOHNSON, Associate Specialist, Driver Education,
Department of Education
SGT. R. J. LANTEIGNE, Operations & Tactics Bureau, Virginia
Beach Police Department
W.T. McCOLLUM, Executive Director, Commission on VASA.P
S.D. McHENRY, Director, Division of Emergency Medical
Services, Department of Health
MAJ. R.R. MINER, Commander, Traffic Division, Fairfax County
Police Department
COMM. S.E. NEWTON, Patrol Division, Albemarle County Police
Department
J.T. PHIPPS, Director, Roanoke Valley ASAP
J.A. SPENCER, ESQ., Assistant Attorney General, Office of the
Attorney General
E.W. TIMMONS, Director of Public Affairs, Tidewater AAA of
Virginia
A.R. WOODROOF, ESQ., Manakin-Sabot, Virginia
PHOTO-RADAR TASK FORCE
William R Archer, Maryland Department of State Police
Captain Braxton G. Bell, Virginia Department of State Police
Nancy G. Dunn, Virginia Department of State Police
Wayne S. Ferguson, Virginia Transportation Research Council
Ronald D. Lipps, Maryland Department of Transportation
Lt. James W Petefish, Virginia Department of State Police
Richard L. Reed, Maryland Department of State Police
James B. Robinson, Virginia Department of Transportation
Captain David L. Tollett, Virginia Department of State Police
iii
TABLE OF CONTENTS
LIST OF TABLES. . . . . . . . . . . . . . . . . . . . . . . . . . vii
LIST OF FIGURES . . . . . . . . . . . . . . . . . . . . . . . . . .ix
ABSTRACT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .xi
INTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Description of the Beltway . . . . . . . . . . . . . . . . . . 2
Operating Speeds on the Beltway. . . . . . . . . . . . . . . . 4
PURPOSE AND SCOPE . . . . . . . . . . . . . . . . . . . . . . . . . 4
BACKGROUND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
History of Speed Enforcement Technology. . . . . . . . . . . . 6
Time-Distance Method. . . . . . . . . . . . . . . . . . . 6
Pacing. . . . . . . . . . . . . . . . . . . . . . . . . . 7
Tachograph. . . . . . . . . . . . . . . . . . . . . . . . 7
Radar . . . . . . . . . . . . . . . . . . . . . . . . . . 7
History of Photo-Radar Technology. . . . . . . . . . . . . . . 8
LEGAL ISSUES. . . . . . . . . . . . . . . . . . . . . . . . . . . .10
Constitutional Issues. . . . . . . . . . . . . . . . . . . . .10
Evidentiary Issues . . . . . . . . . . . . . . . . . . . . . .14
Virginia. . . . . . . . . . . . . . . . . . . . . . . . .14
Maryland. . . . . . . . . . . . . . . . . . . . . . . . .16
Requirements for Legal Service . . . . . . . . . . . . . . . .17
Virginia. . . . . . . . . . . . . . . . . . . . . . . . .18
Maryland. . . . . . . . . . . . . . . . . . . . . . . . .18
Statutory Amendments. . . . . . . . . . . . . . . . . . .18
Film/Photograph Handling Issues. . . . . . . . . . . . . . . .19
Chain of Custody Concerns . . . . . . . . . . . . . . . .19
Privacy Concerns. . . . . . . . . . . . . . . . . . . . .22
Recommended Procedures. . . . . . . . . . . . . . . . . .25
FCC Policy on Photo-Radar. . . . . . . . . . . . . . . . . . .26
METHODS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
Site Visits and Manufacturers' Nonempirical Demonstrations . .27
Field Demonstrations . . . . . . . . . . . . . . . . . . . . .30
Site Selection. . . . . . . . . . . . . . . . . . . . . .31
Site Description. . . . . . . . . . . . . . . . . . . . .32
Photographic Quality and Utility. . . . . . . . . . . . .32
Accuracy of Recorded Speeds . . . . . . . . . . . . . . .35
Effect of Vehicle Clustering on Accuracy
of Speed Measurements. . . . . . . . . . . . . . . .36
Percentage of Usable Photographs of
Vehicles Exceeding Threshold Speed . . . . . . . . .36
Misalignment Flexibility (Cosine Effect). . . . . . . . .37
TABLE OF CONTENTS (cont.)
Ease of Detection by Radar Detectors. . . . . . . . . . .37
Effect of Photo-Radar on Speed Characteristics. . . . . .38
Public Acceptance. . . . . . . . . . . . . . . . . . . . . . .38
RESULTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39
Site Visits. . . . . . . . . . . . . . . . . . . . . . . . . .39
Paradise Valley, Arizona. . . . . . . . . . . . . . . . .40
Pasadena, California. . . . . . . . . . . . . . . . . . .41
Europe. . . . . . . . . . . . . . . . . . . . . . . . . .42
Field Demonstrations . . . . . . . . . . . . . . . . . . . . .44
Photographic Results for Each Manufacturer. . . . . . . .44
Comparisons Among Manufacturers on
Photographic Quality . . . . . . . . . . . . . . . .49
Accuracy of Recorded Speeds . . . . . . . . . . . . . . .59
Effect of Vehicle Clustering on Accuracy of
Speeds/Measurement. . . . . . . . . . . . . . . . . . . .63
Percentage of Usable Photographs of Vehicles Exceeding
Threshold Speed. . . . . . . . . . . . . . . . . . .63
Misalignment Flexibility (Cosine Effect). . . . . . . . .67
Ease of Detection by Radar Detectors. . . . . . . . . . .67
Effect of Photo-Radar on Speed Characteristics. . . . . .68
Public Acceptance Survey . . . . . . . . . . . . . . . . . . .69
SUMMARY OF FINDINGS . . . . . . . . . . . . . . . . . . . . . . . .70
Background . . . . . . . . . . . . . . . . . . . . . . . . . .70
Photographic Quality . . . . . . . . . . . . . . . . . . . . .71
Accuracy of Recorded Speeds. . . . . . . . . . . . . . . . . .71
Efficiency of Photo-Radar. . . . . . . . . . . . . . . . . . .72
Misalignment Flexibility (Cosine Effect) . . . . . . . . . . .72
Radar Detection. . . . . . . . . . . . . . . . . . . . . . . .72
Public Acceptance. . . . . . . . . . . . . . . . . . . . . . .72
CONCLUSIONS AND RECOMMENDATIONS . . . . . . . . . . . . . . . . . .72
LESSONS LEARNED . . . . . . . . . . . . . . . . . . . . . . . . . .73
NOTES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
APPENDIX A: Standard Criterion Photographs. . . . . . . . . . . . .83
APPENDIX B: Public Acceptance Poll Questionnaire. . . . . . . . . .95
APPENDIX C: Description of Photo-Radar Equipment. . . . . . . . . 101
APPENDIX D: Conditions Under Which Manufacturers'
Photographs Were of Highest Quality. . . . . . . . . . . . . 117
APPENDIX E: Calculations of Public Acceptance
Poll Sample Accuracy . . . . . . . . . . . . . . . . . . . . 127
APPENDIX: Model Photo-Radar Statutes for
Maryland and Virginia. . . . . . . . . . . . . . . . . . . . 131
vi
LIST OF TABLES
Table 1: Trip Itineraries and Persons Interviewed During Site
Visits in the United States and Europe. . . . . . . . . .28
Table 2: List of Study Sites . . . . . . . . . . . . . . . . . . .33
Table 3: Number of Photographs Taken for Analysis by Each
Manufacturer. . . . . . . . . . . . . . . . . . . . . . .45
Table 4: Locations of Photographs Taken. . . . . . . . . . . . . .49
Table 5: Weather Conditions Under Which Photographs Were Taken . .50
Table 6: Vehicle Location in Photographic Frame. . . . . . . . . .50
Table 7: Direction of Operation of Photographs Taken . . . . . . .51
Table 8: Mode of Operation When Photographs Were Taken . . . . . .51
Table 9: Format of Photographs Taken . . . . . . . . . . . . . . .52
Table 10: Number of Vehicles in Photograph. . . . . . . . . . . . .52
Table 11: Type of Vehicle in Photograph . . . . . . . . . . . . . .53
Table 12: Lane in which Photographed Vehicles Were Traveling. . . .53
Table 13: Photographic Performance Measures: Receding Traffic . . .54
Table 14: Photographic Performance Measures: Oncoming Traffic . . .54
Table 15: Reasons License Plates in Photographs
Could Not Be Read . . . . . . . . . . . . . . . . . . . .56
Table 16: Reasons Driver's Face in Photographs Could Not Be
Identified. . . . . . . . . . . . . . . . . . . . . . . .57
Table 17: Effect of Highway and Environmental Characteristics on
Photographic Quality for Receding Traffic . . . . . . . .58
Table 18: Effect of Highway and Environmental Characteristics on
Photographic Quality for Oncoming Traffic . . . . . . . .58
Table 19: Differences Between Loop and
Photo-Radar Speed Readings. . . . . . . . . . . . . . . .63
Table 20: Hit Rate for Oncoming Traffic . . . . . . . . . . . . . .64
Table 21: Hit Rate for Receding Traffic . . . . . . . . . . . . . .65
Table 22: Lane Distribution of Usable Photographs . . . . . . . . .66
Table 23: Hit Rates by Distribution of Speeds of Speeding Vehicles
Photographed. . . . . . . . . . . . . . . . . . . . . . .66
LIST OF TABLES (cont.)
Table 24: Maximum Error in Recorded Speed for Misalignments Up to 8
Degrees (Cosine Effect) . . . . . . . . . . . . . . . . .67
Table 25: Radar Detection Distance for Each Piece of Equipment. . .67
Table 26: Comparison of Speed Characteristics at Study Sites. . . .68
Table 27: Opinions Concerning Potential Use of Photo-Radar on
Beltway . . . . . . . . . . . . . . . . . . . . . . . . .70
Table 28: Opinions on Photo-Radar Use by Demographic
Characteristics . . . . . . . . . . . . . . . . . . . . .70
viii
LIST OF FIGURES
Figure 1: Map of Capital Beltway in Virginia and Maryland . . . . . 3
Figure 2: Allowable Differences Between Photo-Radar and Loop
Readings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62
ABSTRACT
Because of increasing difficulties in enforcing posted speed
limits on the Capital Beltway around Washington, D.C., local
officials proposed that experiments be conducted with photo-radar
to determine if that method of automated speed enforcement (widely
used in Europe for about 30 years and very recently employed in the
western United States) could help reduce average speed and speed
variance.
A project task force led by the Virginia Department of State
Police, with assistance from the Maryland Department of State
Police and the Virginia and Maryland Departments of Transportation
and with technical assistance from the Virginia Transportation
Research Council, conducted site visits to cities in Europe and the
United States where photo-radar is being used. The task force also
invited six manufacturers of photo-radar equipment to staff and
demonstrate their equipment. Five of the manufacturers conducted a
2-week series of tests on sections of interstate highways with
varying volumes of traffic and different traffic characteristics.
The tests, which were conducted from June through September 1990,
were designed to provide the evaluators with data on the accuracy,
reliability, and efficiency of each unit (in terms of the number of
speeding cases that could potentially be generated by the use of
photo-radar on the Beltway) and help the study team determine if
photo-radar could be successfully deployed on the Capital Beltway
as an enforcement tool. In addition, the project included an
analysis of legal and constitutional issues associated with photo-
radar use as well as an evaluation of public sentiment concerning
the use of photo-radar on the Capital Beltway. The evaluators
concluded that photo-radar use was feasible on high-speed, high-
volume roads such as the Capital Beltway and, therefore,
recommended efforts to pass state enabling statutes and test
further the efficacy of photo-radar in actual traffic enforcement
conditions. Although the results of the study indicate that it is
feasible to use photo-radar on high-speed multilane roadways,
further study is required to determine its effect on travel speed
and safety.
There are also important operational issues that must be
considered when using this device. Some items of consideration are
identification and selection of operational sites and times to deal
with identified traffic safety and enforcement problems; provision
of equipment-specific training programs for police officers to
ensure the equipment is properly operated; provision for the
availability of properly trained technical support personnel to
ensure the continuing accuracy of the equipment; setting of speed
thresholds that are realistically determined and target the
excessive speeder; number of lanes on the roadway; visual
obstructions on the roadway; and customizing of photo-radar
applications to fit the highway safety problem area.
FINAL REPORT
AUTOMATED SPEED ENFORCEMENT PILOT PROJECT
FOR THE CAPITAL BELTWAY:
FEASIBILITY OF PHOTO-RADAR
Cheryl W. Lynn
Senior Research Scientist
Nicholas J. Garber
Faculty Research Engineer
Wayne S. Ferguson
Senior Research Scientist
Torsten K. Lienau
Research Assistant
Robyn Lau
Graduate Legal Assistant
Janice V Alcee
Graduate Legal Assistant
Jonathan C. Black
Graduate Legal Assistant
Peter M. Wendzel
Graduate Legal Assistant
INTRODUCTION
In response to a growing public concert) about incidents,
crashes, congestion, and delay occurring on the Capital Beltway
around Washington, D.C. (hereinafter called the Beltway), the
Secretaries of Transportation in Maryland and Virginia, in
cooperation with the senior leadership of the Federal Highway
Administration (FHWA) and the National Highway Traffic Safety
Administration (NHTSA), created an interstate task force in 1988 to
study the problems associated with the Beltway and recommend, test,
and implement measures for remediation.
Since one of the concerns of the task force was controlling
speeds on the Beltway, one of their proposals was a demonstration
project to evaluate automated photographic speed enforcement
(APSE). A device with APSE technology, which is capable of
identifying all vehicles being driven above a selected speed using
either radar or some other detector equipment, photographs the
vehicle's license plate and the
driver's face and records the speed of the vehicle and the time of
the photograph. Photo-radar is a form of APSE with radar being used
for detecting a speeding vehicle. The task force was aware of the
limited use of photo-radar in speed enforcement in Pasadena,
California, and Paradise Valley, Arizona, as well as its long-term
use in Western Europe, Scandinavia, South Africa, and Australia. It
was not clear, however, whether photo-radar technology had been
successfully employed on roadways with characteristics similar to
those of the Beltway.
In order to determine the feasibility of using photo-radar
equipment on the Beltway, a study group was formed consisting of
personnel from the Virginia and Maryland Departments of State
Police and Departments of Transportation. The Virginia
Transportation Research Council (VTRC) was selected to staff the
study group and perform the evaluation (Lynn, C., Ferguson, W, and
Garber, N., 1990, PhotoRadar Automated Speed Enforcement.- An
Experimental Application on the Capital Beltway Around Washington,
D.C. VTRC Report No. 90-WP20. Charlottesville: Virginia
Transportation Research Council).
Description of the Beltway
The Beltway is a 64-mile-long limited-access highway
encircling Washington, D.C. The majority of the Beltway, 41.6
miles, is in Maryland; a section of approximately one-tenth mile on
the Woodrow Wilson Memorial Bridge is in Washington, D.C.; and the
remaining 22.1 miles is in Virginia (see Figure 1).
The Beltway was constructed in the late 1950's and early
1960's as a four- and six-lane facility to carry an estimated
annual average daily traffic (AADT) of 40,000. In the 1960's and
1970's, most of the Beltway was widened to eight lanes because
traffic growth was higher than originally assumed; however, there
are still some six-lane sections. Increasing the number of lanes
resulted in a significant reduction in shoulder width, mainly
because of the limited right of way, thus making safe enforcement
by mobile police patrols difficult and hazardous because traffic
stops are made in close proximity to the high-volume travel lanes.
There is a diverse mix of trip purposes, vehicle types, and
traffic patterns associated with the Beltway. Although the Beltway
was originally conceived as a bypass around Washington, expansion
of the metropolitan area and extensive development along the
Beltway and intersecting highway corridors have placed the roadway
within the metropolitan area, rather than around it.
It is estimated that nearly two-thirds of all trips and one-
half of all vehicle miles of travel (VMT) in the Washington
metropolitan area in 1989 were made on the Beltway. Further, in
1989, the traffic volume was estimated at 120,000 vehicles per day;
however, the volume on some sections exceeded 150,000 vehicles per
day.
In 1989, there were approximately 3,034 reported crashes on
the Beltway, an average of 8.3 per day. The estimated cost to
society of these crashes, using NHTSA criteria for cost per
accident, was $69.7 million. The accident rate for the Beltway in
1989 was estimated as 86 accidents per 100 million VMT.
2
Click HERE for graphic.
Operating Speeds on the Beltway
Speed data collected in 1990 for the Maryland and Virginia
sections of the Beltway indicated that average nonpeak speeds
ranged from approximately 58 mph to approximately 64 mph, depending
on the location. About 80 percent of the vehicles exceeded the 55
mph maximum speed limit, and about 40 percent exceeded 65 mph. The
monitoring of 65,850 vehicles traveling in one direction during a
24-hour period in 1988 indicated that the average speed on the
Beltway in Virginia was 64.6 mph. These Virginia data include
speeds for rush-hour traffic, when traveling faster than the posted
limit is generally not possible. Even so, during this 24-hour
period, more than 43 percent of the vehicles exceeded 65 mph. The
number of speed violations on the Beltway for one 24-hour period
(28,503) almost matched the total number of traffic citations for
the entire year of 1988 reported for the metropolitan area by the
Virginia Department of State Police.
In Maryland, speed surveys were conducted at four sites on the
Beltway.
These data show a similar but slightly lower rate of speeding. The
Maryland surveys were conducted for traffic traveling in both
directions on the Beltway and indicated the following fourth
quarter results:
I-495 @ River Road 74,733 vehicles
18,928 exceeding 65 mph (25.3%)
I-95 @ Md. Rt. 214 71,239 vehicles
22,792 exceeding 65 mph (32.0%)
I-95 @ Temple Hills Road 19,823 vehicles
8,474 exceeding 65 mph (42.7%)
I-495 @ Md. Rt. 650 42,846 vehicles
7,031 exceeding 65 mph (16.4%)
These data indicate a high rate of violations of the 55 mph
speed limit and a significant percentage of traffic exceeding 65
mph. Because the shoulders on the Beltway are narrow and because
puffing over vehicles traveling on the inside lanes is dangerous,
speed enforcement capabilities on the Beltway are extremely
limited. Clearly, given the physical limitations on speed
enforcement and the volume of speeding vehicles on the Beltway,
there is a need for innovative methods of speed enforcement.
PURPOSE AND SCOPE
The purpose of this study was to evaluate the feasibility of
using photo-radar technology on high-volume, high-speed
expressways, such as the Beltway. A
4
secondary objective was to compare and contrast the performance of
several brands of photo-radar devices to determine whether they
meet the minimum levels of accuracy, reliability, and efficiency
required for use on the Beltway in accordance with the U.S. legal
system. In addition, the impact of traffic characteristics on
accuracy and reliability was examined. A final objective was to
make recommendations concerning the use of photo-radar on types of
highways other than urban expressways should photo-radar use on
interstate highways prove infeasible.
Information concerning the various brands of photo-radar
equipment and their capabilities was obtained from manufacturers'
sales literature and was corroborated by the results of several
site visits. However, the most important information concerning the
performance of the various devices came from actual demonstrations
on the Beltway and other high-speed interstate highways in Virginia
and Maryland. Thus, the feasibility of using photo-radar was
largely determined by the results of performance testing on site,
rather than by manufacturers' claims or nonempirical demonstrations
in Europe and the United States.
The scope of this project was rather limited. The researchers
assessed the technical and operational feasibility of the different
types of equipment but did not evaluate the effectiveness of the
use of photo-radar in reducing travel speed or the number of speed-
related crashes since it was not possible to give citations during
the demonstration period. In order to avoid creating a hazardous
environment for the manufacturers and the study team, and to avoid
disrupting the traffic flow at the study sites, no special signing
was used. In addition, media coverage was limited to a press
conference on the second Tuesday of each demonstration period.
Thus, no fully coordinated media campaign was employed. A further
limitation on the scope of the study was that Multanova, one of the
major manufacturers, declined to participate in the demonstrations
in Virginia and Maryland. Therefore, there are insufficient data
from which to draw conclusions concerning the accuracy,
reliability, and efficiency of Multanova's equipment.
BACKGROUND
Many people approach the use and evaluation of photo-radar as
if it were a new and uniquely invasive technology. In fact, photo-
radar equipment is simply the combination of several pieces of
previously existing equipment-camera, radar, and electronic
controls-all of which have been used either together or separately
in enforcement and the prosecution of offenses for many years. The
validity and reliability of these older forms of speed enforcement
technology had to be proved to both the police and the courts prior
to general acceptance. Thus, it is an important to consider the use
of photo-radar in the context of (1) the history of speed
enforcement technology, and (2) the history of photo-radar
technology.
5
History of Speed Enforcement Technology
In the past, the introduction of a new and innovative speed
enforcement technology often generated a negative reaction. The
public's distrust of the use of high technology by enforcement
officials is often evidenced by claims that the technology is
simply another attempt by "Big Brother" to invade their lives. When
radar was first introduced in the 1950's, Time Magazine ran an
article headlined "Big Brother Is Driving," the text of which
characterized radar as being "as invisible as the Thought Police in
Orwell's chiller [1 9841. " 1 The use of radar was also challenged
as being unconstitutional.2 The history of speed enforcement is
replete with examples of new enforcement techniques; subsequent
negative public reaction and resistance; and finally, assuming
survival through legal challenges, ultimate acceptance.
Time-Distance Method
The use of the first known method of speed enforcement dates
back to 1902 in Westchester County, New York. This system was
composed of three dummy tree trunks set up on the roadside at 1-
mile intervals. A police officer with a stopwatch and a telephone
was concealed in each trunk. As a speeding vehicle passed the first
trunk, the hidden police officer telephoned the time to the second
police officer, who recorded the time at which the vehicle passed
him and then computed its speed for the mile. If the vehicle was
exceeding the speed limit, the officer telephoned the third police
officer, who proceeded to stop the vehicle by lowering a pole
across the road. The "tree trunk" method was subject to hearsay
objections in court because officers had to testify regarding the
time statements of other officers since there was no way to observe
the vehicle over the entire distance.4
This is an early example of the time-distance method of speed
enforcement. Time-&stance measurements are computed by measuring
the time taken to traverse a distance of known length.5 Several
methods of speed enforcement employ the time-distance principle.
Pavement markings or mirror boxes that are observed by police
officers with a stopwatch have replaced dummy tree trunks, and two-
way radios between patrol cars or aircraft have replaced the
telephone system, but the technique remains much the same.6
The speedwatch, also referred to as the Prather speed device,
was one of the first "electric timers" to employ the time-&stance
principles This device consisted of two rubber tubes that were
stretched across a street at a known distance apart. 'The tubes
were connected to two switches, which were in turn connected to a
control panel containing a stopwatch, a switch, and a reset button.
A police officer was positioned so as to observe both tubes, and
when a vehicle approached, he flipped the switch to activate the
first tube. On contact with the tires of the vehicle, the switch in
the first tube started the stopwatch, which was stopped when the
vehicle hit the second tube. The stopwatch was scaled to reflect
the speed of the vehicle.8 The speedwatch is believed to have been
accurate to within 2 mph, and the officer's testimony as to his
observation of the speeding vehicle and the accuracy of the instru-
ment was admissible in most courts.9
6
The most recent technique employing time-distance measurements
is the visual average speed computer and recorder (VASCAR). VASCAR
is a computerized system that mechanically computes the speed of a
car by measuring the distance between two fixed markers and the
time traveled, thereby giving the observing police officer a quick,
easily readable speed determination. 10
In 1947, only 1 state used a time-distance device," but by
1970, 34 states were employing at least one-the majority using
VASCAR or aerial surveillance.12 Because time-distance devices have
been categorized as "speed traps," their use has been prohibited in
at least 2 states: California and Washington. 13
Pacing
Another widely used method of speed enforcement in the 1940's
was "pacing."14 Police officers paced a speeding vehicle by
following it for a specified distance and observing the speedometer
of the police vehicle to calculate the average speed of the paced
vehicle over the distance. In 1947, 20 percent of the states re-
quired pacing before apprehension of a speeding driver.15 A large
percentage of states used unmarked cars, identifiable only by
decals, and/or motorcycles as pacing vehicles. 16 Because pacing
depends on the accuracy of the pacing vehicle's speedometer, many
states adopted the use of calibrated speedometers and regulations
defining the frequency at which speedometers must be calibrated. 17
Tachograph
The tachograph, also referred to as a tactograph or
tachometer, was a speed enforcement method used by trucking
companies to control the speed of truck drivers. The tachograph
contained a clock with a paper dial attached to the driveshaft or
transmission of the truck. The dial recorded the speed of the truck
at any given time. 18 The chart produced by this device was used to
corroborate the testimony of the arresting officer;19 ironically,
however, it was often admitted into evidence to prove the innocence
of the implicated driver.20
Radar
Police radar was introduced in the late 1940's and early
1950's. Although generally referred to as "radar," police radar is
not technically radar. True radar has the ability to measure an
object's distance, direction, and size as well as its speed, but
police radar measures only speed. Police radar operates according
to the scientific principle known as the Doppler effect: the
frequency of sound waves (or microwaves) being emitted by or
reflected off of an object will vary in direct relation to the
speed of the object itself. The Doppler effect is noticeable in
everyday life in the rising and falling of a car horn's pitch as
the car approaches and passes. Police radar transmits microwaves at
a set frequency. When the microwaves are reflected off of a
vehicle, the frequency of the returning microwaves shifts because
the vehicle is in motion. This shift in the original frequency, the
Doppler shift, is measured by the radar device, which converts the
signal into a measurement of the vehicle's speed.
7
An early hurdle encountered by police radar (hereinafter
called "radar") was evidentiary in nature. Before judicial notice
was taken of the underlying principle involved, courts required
that an expert witness testify as to radar's accuracy and re-
liability.21 The Virginia Supreme Court was among the first courts
to take judicial notice of radar's underlying principle, thereby
eliminating the need for expert testimony.22 However, testimony as
to the accuracy of the particular machine used to detect the
violation is still required.
Constitutional questions have also arisen in radar cases, as
they invariably do whenever a new scientific technique becomes
useful in enforcement.23 The Virginia statute providing that radar
evidence constitutes prima facie evidence of speeding was found to
be constitutional under the Fourteenth Amendment of the U.S.
Constitution.24 The defendant in the case argued that the provision
was tantamount to his being presumed guilty25. However, the court
held that the defendant was still presumed innocent under such a
standard.26 A Pennsylvania due process claim based on the alleged
instantaneousness of the machine's determination and the potential
for error was likewise denied.27 In denying the claim, the court
noted the complete absence of cases holding the use of radar for
speed measurement to be unconstitutional.28 Cases raising the issue
of a citizen's constitutional right against self incrimination have
likewise been unsuccessful.29
History of Photo-Radar Technology
Law enforcement's latest innovative technology for the
enforcement of speed laws is photo-radar. Photo-radar equipment
combines a camera and radar with electronic controls to detect and
photograph a speeding vehicle. The unit can photograph the driver's
face and the front license plate if deployed to photograph oncoming
traffic or the rear license plate if deployed to photograph
receding traffic. The license number of the speeding vehicle is
extracted from the picture, and a citation is sent to the
registered owner of the vehicle. The radar used in photo-radar
equipment operates on the same Doppler principle as the radar used
by the police.
Although photo-radar is a relatively new technology in the
United States, it is not the first speed detection device to use a
camera. In 1910, a device known as a photo speed recorder was used
in Massachusetts.30 The photo speed recorder consisted of a camera,
synchronized with a stopwatch, that took pictures of a speeding
vehicle at measured time intervals. The speed of the vehicle was
determined by a mathematical calculation based on the reduction in
size of the vehicle in the photograph as it moved farther away from
the camera. This photographic evidence was held admissible by the
Supreme Judicial Court of Massachusetts, and the scientific
approach was judged more reliable than, eyewitness testimony
because it did not rely on the "fluctuations of human agencies.
However, in 1955, the unattended use of the photo-traffic
camera (FotoPatrol) was prohibited in New York because of the
difficulty in identifying the driver of the vehicle.32 The Foto-
Patrol device, a camera mounted on the side of the road
8
activated by an electronic impulse when passed by a vehicle
traveling in excess of a predetermined speed, took a picture of the
rear license plate only, making it impossible to identify the
driver. The court was unwilling to adopt the presumption that the
driver was the registered owner of the vehicle, absent any
corroborating evidence, and prohibited the use of Foto-Patrol
unless it was staffed by an attending officer available to stop and
identify the driver on the spot.33
The problem of driver identification was resolved by the Orbis
In (Orbis) system introduced in the late 1960's.34 Orbis operated
much like an advanced Prather speed device that employed a
camera.35 The contacts the vehicle ran over were 72 inches apart
and connected to a computer that triggered the camera, which was
set up to capture the vehicle's front license plate and the
driver's face if the vehicle's speed exceeded a preset limit.36
When Orbis was introduced, it encountered a unique form of
resistance. - 37 To avoid being recognized, people would speed by
the Orbis machine wearing a Halloween mask. 38- Such a tactic would
be illegal in Virginia, but not in Maryland, because of a statute
that prohibits those over 16 years of age from wearing a mask in
public.39 Orbis was abandoned for administrative reasons.40
Research did not identify any cases that successfully challenged
Orbis on legal grounds, and a study prepared for the U.S.
Department of Transportation indicated that the device was probably
constitutional.41
It is uncertain whether photo-radar will be accepted by the
public. Previous speed enforcement techniques usually gained
acceptance if the technology proved accurate and if they survived
the initial constitutional and evidentiary challenges. However,
even after a technology gains acceptance, drivers have often
undertaken efforts to thwart the technology's effectiveness. One
example of a popular form of resistance to speed detection
technology is the use of a radar detector. Radar detectors, which
are illegal in Virginia,42 sound a warning to the driver when they
detect the microwave signal emitted by the radar unit. Drivers have
also tried using other methods to avoid being caught speeding by
radar.43 These methods included using transmitters designed to
disrupt the radar signal, putting nuts and bolts in the hubcaps,
painting the fan blades with aluminum paint, and attaching hanging
chains to the undercarriage of the car.44 There is even a 160-page
book entitled Beating the Radar Rap.45 Photo-radar will no doubt
encounter many, if not all, of these methods of resistance.
However, if photo-radar is proven to be accurate, and if it is able
to withstand the initial legal challenges, then it should gain
acceptance as an effective tool in speed enforcement.
There is evidence that the public may support photo-radar use
in residential settings. In Pasadena, California, and Paradise
Valley, Arizona, where photo-radar has been used in residential
settings on local, noninterstate roadways, a majority of
respondents in public opinion polls have been in favor of photo-
radar use. However, one must interpret these findings in light of
the fact that more than 90 percent of those cited for speeding in
these two locations are nonresidents. This will not likely be the
case in Virginia and Maryland, especially if photo-radar is used on
the Beltway.
9
LEGAL ISSUES
Constitutional Issues
If there is one constant in speed enforcement, it is that
drivers will contest speeding citations. Because constitutional
attacks are easily fashioned to assert nearly any position, it can
be expected that implementation of photo-radar in a state will
generate constitutional challenges to its use. However, although
constitutional attacks are easily levied, they are not necessarily
successful. Current jurisprudence supports the constitutionality of
photo-radar despite potential challenges to its use.
Although an attack might be leveled against photo-radar on the
grounds that photographs produced by photo-radar violate the
automobile operator's zone of privacy, 46 such an assertion does
not reflect the scope of the zone of privacy. The first explicit
discussion of a right to privacy by the US. Supreme Court appeared
in Griswold v. Connecticut, 47 in which the appellants challenged a
Connecticut statute prohibiting the distribution of birth control
information to married persons.48 The Court held that the
Connecticut statute was unconstitutional, concluding that the
marital relationship was such that it belonged within a class of
fundamental rights deserving of special protection and that the
Connecticut statute unnecessarily intruded into the relationship.49
But the zone of privacy is narrowly construed. The rights
falling under the zone of privacy are "limited to those which are
'fundamental' or 'implicit in the concept of ordered liberty."'60
The activities found by the Supreme Court to fall within the zone
of privacy include "matters relating to marriage, procreation,
contraception, family relationships, and child rearing and
education."" Placing a right within the zone of privacy limits the
state's regulatory power over the actiVity.,52 The operation of an
automobile simply does not fall within the category of fundamental
rights protected by the zone of privacy. To the contrary, the
Supreme Court considers a person's expectation of privacy in an
automobile to be quite limited, and automobile operation is
properly subject to significant state regulation.53
Another possible attack against photo-radar could be made
under the Fourth Amendment right to be free from unreasonable
searches54 on the grounds that photo-radar photographs constitute a
Fourth Amendment search. Therefore, photo-radar use is subject to
the Fourth Amendment's probable cause and warrant requirements.
Under the Fourth Amendment, a person has a constitutional right to
freedom from unreasonable search and seizure in circumstances where
the person has a reasonable expectation of privacy.55 This
constitutional right is protected through the requirement that a
police officer have probable cause and a warrant in order to engage
in certain types of searches.56
Unless a person exhibits a reasonable expectation of privacy
under the circumstances, the Fourth Amendment warrant and probable
cause requirements are not triggered.57 However, a person has a
lowered expectation of privacy in an automobile - Moreover, "what a
person knowingly exposes to the public" receives no
10
"Fourth Amendment protection. "59 For this reason, in United States
v. Knotts, the Supreme Court upheld the warrantless placement by
law enforcement officers of a beeper in an automobile to monitor
the vehicle's movements.60 According to the Supreme Court, a person
traveling in an automobile on public roads has no reasonable
expectation of privacy in his or her movements since this
information is knowingly exposed to all who care to look.61
Likewise, photo-radar merely photographs that which a person
knowingly exposes to the public while driving-the person's
likeness. Because of this, the use of photo-radar violates no
reasonable expectation of privacy and, therefore, is not subject to
the Fourth Amendment warrant and probable cause requirements.
A further claim that might be raised against photo-radar is
that its use chills the freedom of association found by the Supreme
Court to be implied by the First Amendment.62 Such a claim asserts
that both drivers and passengers might avoid traveling in vehicles
with individuals with whom they would normally associate in order
to avoid being officially observed and photographed by photo-
radar.63 This argument misconstrues the scope of associational
rights. The Supreme Court has delineated two types of associational
rights: (1) freedom of expressive association, and (2) freedom of
intimate association.64 The freedom of expressive association
protects organization within groups for the exercise of First
Amendment rights, such as freedom of speech and region.65 The
freedom of intimate association is an outgrowth of the privacy
doctrine and protects an individual's right to engage in intimate
relationships without threat from excessive governmental
regulation.66
Speed enforcement through photo-radar technology does not
compromise freedom of expressive association for two reasons.
First, a claim that photo-radar use might prevent certain
individuals from traveling with persons with whom they would
normally associate will not support a claim for infringement of
freedom of expressive association. A showing "of specific present
objective harm or a threat of specific future harm" to
associational rights and First Amendment rights is necessary to
support a freedom of expressive association claim when government
regulations will only indirectly affect the exercise of First
Amendment rights.67 In Laird v. Tatum68 and Donohoe v. Duling,69
the activities of the plaintiffs' lawful political groups were un-
der surveillance. The Laird plaintiffs argued that surveillance by
U.S. Army observers of the activities of the political groups had a
chilling effect on their First Amendment right to free speech and
freedom of association.70 The plaintiffs in Donohoe claimed that
the taking of pictures by uniformed police officers of persons
involved in demonstrations violated the demonstrators' First
Amendment rights.71 The Supreme Court in Laird held that a claim of
a hypothetical chilling effect on First Amendment and associational
rights would not support a freedom of expressive association claim
if the government regulation did not directly prohibit First
Amendment activity.72 Thus, the Laird and Donohoe courts held that,
where government activity prevents exercise of First Amendment
rights indirectly, a freedom of expressive association claim
requires a specific showing of an objective present harm or
threatened future harm.73
Second, the freedom of expressive association claim against
photo-radar is far weaker than the claims presented in Laird and
Donohoe since photo-radar speed enforcement is not solely directed
at groups organized for the purpose of exercising First Amendment
rights. Freedom of expressive association protects association only
for the purpose of exercising First Amendment rights.74 Successful
freedom of association claims involve government regulations
targeting the activities of particular groups organized
specifically to exercise First Amendment rights.75 The only group
targeted by photo-radar would be speeding drivers, who certainly do
not represent an organized group, much less a group organized for
First Amendment purposes.
Moreover, photo-radar use will not provide a basis for a
freedom of intimate association claim. Although the boundaries of
intimate association remain largely undefined, as an outgrowth of
the zone of privacy, it has been used to strike down regulations
that interfere with certain marital and familial relationships.76
Successful freedom of intimate association claims involve statutes
that directly interfere with marital and familial relationships.77
The connection between photo-radar use and association through
intimate relationships is attenuated at best. Photo-radar clearly
does not prevent individuals from engaging in intimate
relationships with family members, or any other person for that
matter, and, therefore, does not implicate the freedom of intimate
association.
An equal protection claim based on the fact that not all
speeders would be detected by photo-radar and cited for speeding 78
would also most likely fail. Because a photo-radar unit requires 1
second to reset itself after photographing a violator, not all
speeding drivers passing through the photo-radar field would be
detected. Thus, not all those violating the speed laws receive the
same treatment.
However, to launch a successful equal protection claim, the
plaintiff must prove that the standard used to select the claimant
for enforcement "was deliberately based on an unjustifiable
criterion such as race, religion, or other arbitrary classifica-
tion.79 The inability to prosecute all violators will not provide
the basis for an equal protection claim.80 Since the determination
of who is missed by photo-radar and who is caught is based on the
technical abilities of the system and not on an intentional
decision to discriminate based on a suspect classification, an
equal protection challenge to the use of photo-radar would almost
certainly fail.
Finally, because a citation for a speeding violation detected
by photo-radar must pass through a development process and is
issued through certified mail, there is a delay between the time of
the violation and the issuance of a citation that could undercut
efforts by a violator to prepare a legal defense. For this reason,
a ticketed driver could assert that photo-radar use constitutes a
denial of due process of law. Currently, the cities of Paradise
Valley, Arizona, and Pasadena, California, which employ photo-
radar, have circumvented due process claims by issuing citations
within a given time period following the offense and by deploying
signs providing considerable warning of approaching photo-radar
units. Still, photo-radar is subject to a due process claim on the
grounds that the element of delay hampers the ability to gather
witnesses and evidence and thus to prepare a proper defense.
However, the delay involved in citing an alleged violator
using the photoradar process is relatively short, reducing the
possibility that a defendant will lose
12
access to witnesses or evidence. Access to evidence with photo-
radar may, in fact, be better than with a conventional stop since
photo-radar creates a photographic record of the scene where the
speeding violation occurred. Further, in United States v.
Delario,81 the defendant argued that a pre-indictment delay of more
than 1 year constituted a denial of due process. The Court found
that the argument lacked merit and held that the defendant would
have to show that the delay was a deliberate attempt by the
government to n a tactical advantage and had resulted in actual and
substantial prejudice.82 Because the delay involved in issuing
photo-radar citations cannot reasonably be viewed as an attempt by
the government to gain a tactical advantage, case law suggests that
a due process claim against photo-radar is also likely to fail.
If constitutional attacks against photo-radar are
unsuccessful, a ticketed driver might pursue civil liability
against the state under the common law right of privacy. The common
law right of privacy is a tort action created by state courts83
permitting recovery of damages for an invasion of privacy as
defined by state law.
A state law action for invasion of privacy might be brought
against the use of photo-radar on the basis that the unauthorized
taking of a person's photograph constitutes an invasion of
privacy.84 A common law right of privacy claim against a local
government for the use of photo-radar is likely to fail in Virginia
and Maryland for several reasons.
First, courts have repeatedly held that an individual's
privacy must yield to the reasonable exercise of a state's police
power.85 Included within the state's police power is the authority
to photograph persons charged with a crime.86 Thus, in Downs v.
Swann, the Maryland Court of Appeals rejected a claim for invasion
of privacy against the Baltimore Police Department on the grounds
that photographing and fingerprinting a suspect charged with a
crime did not violate the suspect's right - 87 As long as the
police department neither published the pictures nor gave of
privacy. The pictures of suspects not yet convicted to a rogue's
gallery, the police department was not subject to the common law
right of privacy.88 Second, state courts outside Virginia and
Maryland have indicated that there is no invasion of privacy under
the common law right of privacy if the photographing of an
individual by a law enforcement agency does not violate a
reasonable expectation of privacy under the Fourth Amendment.89
These opinions suggest that a law enforcement agency may photograph
whatever a person knowingly exposes to the public without violating
the common law right of privacy.
Finally, although no Virginia state court has spoken on the
issue, the U.S. Court of Appeals for the Fourth Circuit has stated
that no common law right of privacy exists in Virginia.90 The
Fourth Circuit construes Virginia law as providing merely a
statutory right of privacy, preventing the use of photographs for
commercial purposes only.91 Under the federal court's
interpretation, Virginia law does not countenance a damages action
against a law enforcement agency for the use of photoradar
photographs in speed enforcement. For these reasons, Virginia and
Maryland courts would most likely permit use of photographs
produced by photo-radar in legitimate speed enforcement efforts
without threat of civil liability under the common law right of
privacy.
13
Evidentiary Issues
Photo-radar devices detect speeders by radar and then
photograph the front or rear license plate of the vehicle and, in
most cases, the driver. In Pasadena and Paradise Valley, police
officers are always present when the devices are in operation. If
the registered owner of the vehicle challenges the citation, the
attending officer testifies in the court proceeding as to the
accuracy of the background scene depicted in the photograph and
compares the likeness of the driver in the photograph to the reg-
istered owner. No appellate challenges regarding evidentiary issues
have occurred in either locality.
A photograph is usually admitted into evidence under the
pictorial testimony theory. Under this theory, photographic
evidence is "admissible only when a witness has testified that it
is a correct and accurate representation of relevant facts person-
ally observed by the witness. "92 However, it is not necessary that
the witness be the actual photographer.93 The witness is required
to know only about "the facts represented or the scene or objects
photographed, and once this knowledge is shown he 9794 can say
whether the photograph correctly and accurately portrays these
facts. Prosecutors in Pasadena and Paradise Valley have proceeded
under the pictorial testimony theory when introducing photo-radar
photographs into evidence. Because their photo-radar devices are
attended by police officers, the officers can testify in court that
the photographs are accurate representations.
For any proposed system for use on the Beltway, it is likely
that the device will be attended by a police officer. However, if
unattended use is anticipated, a different theory must be used in
order to admit the photographs into evidence. This newer theory of
admission is referred to as the "silent witness" theory.95 Under
this doctrine, photographs constitute "'substantive evidence' in
the sense that photographic evidence alone can support a finding by
the trier [of fact],96. Thus, under the silent witness doctrine,
"photographic evidence may draw its verification, not from any wit-
ness who has actually viewed the scene portrayed on the film, but
from the reliability of the process by which the representation was
produced."97 The silent witness theory, however, is not accepted in
all jurisdictions.98
Virginia
In Virginia, photographic evidence is admissible under both
the pictorial testimony theory and the silent witness theory.99 The
pictorial testimony theory remained the sole theoretical basis for
the admission of photographic evidence until the 1972 Virginia
Supreme Court ruling in Ferguson v. Commonwealth.100 The sole issue
in that case was whether photographs could be admitted under the
silent witness 101 theory.
In Ferguson, the defendant was convicted of forgery for
cashing a forged check at a drugstore equipped with a Regiscope
camera.102 The Regiscope camera photographed each check-cashing
transaction, with the photograph including the person presenting
the check, the identification presented by the person, and the
check itself.
14
This process was accomplished by the person placing the check
and the identification at the base of the camera while standing at
the cashier's window where the camera was installed. Each
transaction was assigned a number that was stamped on the check
prior to the time the photograph was taken. The check and the
transaction number were used to identify the transaction when a
photograph was requested from the Regiscope Company.
In the Ferguson case, the store manager who had loaded the
film also removed the film and sent it to the Regiscope Company to
be developed. Regiscope then delivered the photograph of the
defendant to an employee of the drugstore, who in turn delivered it
to the police. During the ensuing trial, "no witness testified that
the photograph depicted a scene or event as witnessed by him"103.
The Virginia Supreme Court determined that "the evidence was
sufficient to provide an adequate foundation assuring the accuracy
of the process" and thus that the photograph was properly admitted
into evidence under the silent witness theory.104
The Code of Virginia expressly provides for the admissibility
of photographs in particular kinds of cases under the silent
witness theory. For example, in larceny prosecutions, photographs
of the goods allegedly stolen may be introduced as evidence, rather
than the goods themselves. In Saunders v. Commonwealth,105 the Vir-
ginia Court of Appeals examined in detail this codification of the
silent witness theory The court concluded that each of the
statutory requirements must be met in order for the photograph to
be admissible. Since the statute required the arresting officer to
sign the photograph, his failure to do so resulted in the court
finding that the photograph could not stand as substantive evidence
under the silent witness 106 theory. However, the court ruled that
the photograph was admissible under the pictorial testimony theory
because the arresting officer testified that the photograph
accurately represented what he observed and photographed.107
Under Ferguson and Saunders, it appears that the silent
witness theory provides an acceptable basis for the admission of
photographic evidence in Virginia in certain contexts. In Ferguson,
the Virginia Supreme Court carefully examined the Regiscope process
before determining that it presented an "adequate foundation as-
suring the adequacy of the process."I-08 Although the silent
witness theory has been codified for limited circumstances,
Saunders demonstrated that such statutes are to be narrowly
construed. Under both holdings, the procedures used in obtaining
and bringing the photographs to trial are crucial in determining
their admissibility as evidence.
To determine whether photographs taken by an unattended photo-
radar system would be admissible under the silent witness theory,
the test that must be applied is "whether the evidence is
sufficient to provide an adequate foundation assuring the accuracy
of the process producing it."109 It is useful to compare the photo-
radar process to the Regiscope process to speculate whether photo-
radar photographs would meet this test. If the two processes are
sufficiently similar, it is likely that photo-radar photographs
would be admissible as evidence under the silent witness theory.
15
The photo-radar process appears to be substantially similar to
the Regiscope process. A police officer will load the film. When
the radar device detects a speeding vehicle, the camera will
photograph the vehicle, thereby recording the front license plate
and the face of the driver, or the rear license plate only. The
police officer will unload the film and send it either to the
photo-radar company or to a police photo-processing laboratory. A
citation will then be issued to the registered owner(s) of the
vehicle. As with the Regiscope system, if the photograph is
required for evidence in a trial, the photo-processing laboratory
can develop the film and send the police the photograph that will
be identified by the license plate number.
The Regiscope system and photo-radar system differ in that the
Regiscope appears to be manually operated, with the cashier
controlling the camera, and the photo-radar camera is automatically
activated when the radar detects a speeding vehicle. It is possible
that photo-radar equipment would be staffed in some cases. Whether
operated automatically or by police officers, evidence of the
technical accuracy of the activation device would have to be
presented to the court in order for a photo-radar photograph to be
admissible.
Another difference between the two systems that may bear on
the accuracy of the process is that the Regiscope system is set up
inside a store that presumably is constantly monitored by
employees. The photo-radar system would be set up outdoors, and
tampering with the system would be possible in un-monitored
locations. This difficulty could be remedied by producing evidence
that tampering does not affect the accuracy of the system or that
tampering did not occur in the situation in question.
One other accuracy problem may arise in connection with the
use of the photo-radar system. In some instances, more than one
vehicle may be shown in the same photograph, thereby creating
difficulty in determining which of the drivers was speeding.
Charles Oringer, Town Attorney for Paradise Valley, explained that
this difficulty is easily resolved. Older photo-radar cameras have
a 29-degree field angle; the newer models have a 22-degree field
angle. The radar equipment has a 5-degree field angle. On the
photograph taken by the photo-radar device, the portion of the
photograph containing the radar field can be distinguished. Thus,
the car in that portion of the photograph is the speeding vehicle
detected by the radar system. Some photo-radar systems use a
template, which is placed over the picture, to identify the
speeding vehicle when there is more than one vehicle in a
photograph.
Although the Virginia courts and the Virginia legislature have
not specifically addressed the admissibility of photo-radar
photographs under the silent witness theory, it appears that the
photo-radar process can meet the accuracy test laid down in
Ferguson. Thus, it is likely that photo-radar photographs may be
admissible even if no attending police officer can testify as to
the accuracy of the background scene.
Maryland
The acceptability of the silent witness theory in Maryland is
not so clear as in Virginia. In Sisk v. State,110 the defendant
appealed the admission of Regiscope pho-
16
tographs in the retrial of his forgery case. In the first hearing,
the reviewing court determined that the Regiscope photograph had
not been sufficiently authenticated under either theory of
admission for photographic evidence. 111 During the retrial, two
types of authentication evidence were admitted: (1) testimony
regarding the accuracy of the Regiscope system, and (2) testimony
by a store employee identifying the 112 In its review of the
retrial, the Maryland Supreme Court background scene.stated that
"this seems to be the first time that we have been called upon to
consider, specifically, the [silent witness] rule." 113 Although
the court ruled that the Regiscope photograph had been sufficiently
authenticated, it discussed both theories and did not explicitly
state under which theory the photograph had been admitted. 114
It is possible that this case stands for the proposition that
the silent witness theory may be used for the admission of
photographic evidence in Maryland courts. Sisk differs from
Ferguson, however, in that no witness was required to testify as to
the accuracy of the photograph in the Virginia case. It is possible
that the Maryland court was fashioning a modified silent witness
theory, which imposes the additional requirement that a witness
testify as to the accuracy of the photograph. Under the facts of
Sisk, it appears that it is not necessary that the witness be
present at the time the photograph is taken in order to testify as
to its authenticity if other evidence ensuring the accuracy of the
process of identifying speeding vehicles and photographing them is
also admitted. In the case of photo-radar, this would mean that the
police officer who loaded the film would testify as to the accuracy
of the background scene. There have been many technological
advances in photography and radar in the 26 years since Sisk was
decided. It is possible that courts would now be less skeptical of
the accuracy of the process and therefore less likely to require a
witness to testify regarding its accuracy.
No other Maryland case addresses the acceptability of the
silent witness theory. Although the Maryland Supreme Court
discussed the silent witness theory in favorable terms and stated
that the issue before the court was admissible under the silent
witness theory, the holding in Sisk does not clearly state that the
theory is acceptable in Maryland. Given the lack of precedent for
this theory and the lack of clarity in the one case addressing the
issue, the acceptability of the silent witness theory in Maryland
is uncertain.
Requirements for Legal Service
Some of the photo-radar systems under consideration for
installation on the Beltway use a procedure whereby the company
providing the photo-radar service mails the speeding citation to
the residence of the alleged offender. This procedure would present
difficulties in both Maryland and Virginia because both mandate
personal service for the issuance of traffic citations. It is clear
that the method of service presently employed by photo-radar
providers is inconsistent with the statutory service requirements
of Maryland and is likely to be inconsistent with the statutory
service requirements of Virginia.
17
Virginia
"Personal service of a traffic citation" involves several
actions by the arresting officer. When a driver is detained by a
police officer for any violation of Title 46.2 that is "punishable
as a misdemeanor," Virginia law requires the driver to give a
written promise to appear for a hearing. 115 This requirement is
normally fulfilled by the signature of the driver at the time of
the issuance of the traffic citation. Because speeding is a
violation punishable as a misdemeanor,116 the offense is subject to
the requirements of Section 46.2-936, requiring a written promise
to appear from a driver detained by a police officer for a speeding
violation.
It is questionable whether the written promise requirement
would apply to the photo-radar method because the prerequisite to
the requirement is the detention or custody of the driver. 117 When
a driver is not detained, a written promise may not be necessary.
This would be the case where a citation is mailed to the residence:
no interaction between the driver and the police officer would be
involved. It is not possible to determine in advance whether
Virginia courts would accept this narrow construction of the
statute.
Maryland
Maryland state law requires that a driver charged with a
traffic violation acknowledge receipt of the citation by signing it
at the time of issuance. 118 An Attorney General's opinion issued
in 1979 confirmed this requirement. 119 That opinion stated that
the signature requirements of Section 26-203 of the Transportation
Code also applied to Section 26-201(a) of the same article.120
Section 26-201(a) contains a list of statutes for which police
officers are given authority to charge violators. 121 Included in
the list are all Maryland vehicle laws. 122 Speeding offenses,
codified at Section 21.801 et seq. of the Transportation Code, are
a part of Maryland's vehicle law and therefore are subject to the
signature requirements of Section 26-203.
It is clear that under Maryland law the mailing of citations
to the residence of the alleged offender would violate the service
requirements incorporated in the Maryland Transportation Code,
Section 26-203. Section 26-203 specifically requires at the time of
issuance the driver's signature as acknowledgment of receipt of a
traffic citation. Therefore, using photo-radar in Maryland would
require either statutory revision or personal issuance of the
citations by police officers.
Statutory Amendments
Legislative action in both Virginia and Maryland would assist
in the implementation of photo-radar as a viable speed detection
system. Specifically, the adoption of statutes that provide for
service of traffic citations by mail would facilitate
implementation, as would codification of the silent witness theory
of admissibility for photo-radar photographs. In Virginia,
violation of the provisions for use of high occupancy vehicle (HOV)
lanes does not require personal service of the citation. However,
in Virginia, although the HOV violation is a type of traffic
infraction, it is not a misdemeanor and is treated much as a
parking ticket. Thus, the HOV prece-
18
dent does not apply to the several requirements for the misdemeanor
speeding violation.
Film/Photograph Handling Issues
Both manned and unmanned photo-radar sites will require manual
camera loading and unloading, laboratory photo processing, and
storage of the resulting negatives and prints. In developing
operational procedures to carry out these functions, two additional
issues arise. The first involves how the film and photographs are
physically stored between the time of an alleged speeding violation
and the admission of the photo-radar photograph into evidence. The
procedures instituted for handling and developing the film must
ensure that the 'chain of custody" provides reasonable certainty
that physical tampering or alteration does not occur to either the
film or the photograph. The second issue involves individual
privacy rights. The privacy of individuals in Virginia and Maryland
is protected under both common law and statutory enactments. Thus,
it is necessary to ensure that the photographic handling and
storage procedures do not interfere with these privacy
entitlements. The following subsections examine Virginia and
Maryland law with regard to chain of custody requirements and
individual privacy rights and recommend operational film/photograph
handling procedures that conform to the provisions of the law in
both jurisdictions.
Chain of Custody Concerns
Due to the ease with which film and pictures can be altered,
photographs offered under the silent witness theory must be
authenticated. Thus, the film/ photograph handling procedures must
ensure that photographs used in cases involving a contested
speeding ticket are genuine. Authentication is accomplished by
establishing the chain of custody of photographs prior to their
introduction into evidence. This chain of custody is usually
established by eliciting testimony from each successive custodian
of the film/photograph to show that the original film was delivered
to the laboratory and developed without any tampering and that the
photograph introduced in court was reproduced from the original
film. In addition, chain of custody authentication typically
requires that the evidence be secure when not in use and that it is
made available only to those individuals directly involved in its
processing.
In Virginia, the general chain of custody rule (as stated in
Reedy v. Commonwealth of Virginia) is that "evidence of the
physical properties of an item ... requires proof of the chain of
custody to establish with reasonable certainty that the material
was not altered, substituted, or contaminated."123 Only one
decision, however, has discussed the operational procedures
required with respect to the handling and processing of film and
photographs. In Ferguson v. Commonwealth, a store used a Regiscope
camera to photograph every check-cashing transaction that took
place. The film was sent to the Regiscope Corporation for
processing and storing. Upon learning that a check had been forged,
the store owner requested a
19
photograph of a particular transaction from Regiscope. Regiscope
then sent a print from the negative to one of the store's
employees, who in turn took it to the police. The Ferguson court
held that evidence which established the reported sequence of
events was "sufficient to provide an adequate foundation assuring
the accuracy of the process producing [the picture]" and thus
admitted the photograph into evidence.
Another chain of custody decision, Robertson v. Commonwealth
of Virgina125 is also applicable to the photo-radar film handling
procedures. In Robertson, the court held that the mailing of a
sealed package containing evidence did not upset the chain of
custody since, in the absence of any evidence of tampering or mis-
handling, it will be presumed that the U.S. Postal Service has
properly discharged its duties.
In developing operational procedures that conform to the
Reedy-Ferguson Robertson chain of custody rules, it is helpful to
examine (1) the procedures the Virginia State Police use to ensure
the admissibility of photographic evidence in court, and (2) the
film-handling procedures required in other jurisdictions. According
to Lt. Col. C. M. Robinson, the Virginia State Police use the
following procedures for the handling and processing of photographs
admitted into court. The police officer who took the picture
delivers the film to the police photo laboratory, with a request
specifying the number and size of the prints required. The
laboratory logs in the film, develops it, makes prints, and returns
copies of the prints in a sealed package to the officer in charge
of the case by U.S. mail. The negatives are retained at the
laboratory. During this process, the film/photographs are stored in
limited access areas to prevent tampering prior to trial.
As to other jurisdictions, in State v. Young,126 a Maine
appellate court ruled that the following was sufficient to
establish the authenticity of photographs from a bank surveillance
camera: (1) testimony of the bank manager as to the installation
and field of view of the camera; (2) testimony of an employee of
the company that installed the camera as to the camera's operation
and periodic testing; (3) testimony of the person who removed the
exposed film; (4) testimony of each of the law enforcement officers
who had custody of the film from the time it was taken from the
camera until the time of the trial; and (5) testimony of the bank
teller as to the activation of the camera during the robbery.
Similarly, in Groves v. Indiana,127 the Supreme Court of Indiana
held that "in cases involving automatic cameras ... there should be
evidence as to how and when the camera was loaded, how frequently
the camera was activated, when the photographs were taken, and the
processing and chain of custody of the film after its removal from
the camera."128
Furthermore, some courts have approved even less stringent
chain of custody procedures when photographs are admitted into
evidence under the silent witness theory. For example, in Molina v.
State,129 an Alabama. appellate court held that "As long as
satisfactory evidence of the integrity of a film or videotape is
presented, stringent foundational requirements, such as proof of a
continuous chain of custody, are now almost universally rejected as
unnecessary."130 The court then further noted that "[an example of
a film or tape for which chain of custody might be one
20
appropriate way of establishing authenticity would be a film or
tape made with an automatic camera that recorded an event when no
human beings were present. But even in this situation, rather than
resorting to proof of chain of custody, it usually should be
possible to authenticate the film or tape in some other way, such
as by the testimony of a photographic expert who has determined
that it has not been altered in any wa and was not built up or
faked."131 Similarly, in Stark v. State of Indiana, 112 the Indiana
Supreme Court held that the admission 'into evidence of a
photograph taken by a Regiscope camera was proper even though the
"state provided neither evidence about the manner in which the
photograph was processed nor a complete chain of custody.'133
In Maryland, the common law chain of custody rule requires
that there be a "reasonable probability ... that no tampering
occurred while the evidence was in the state's possession and that
it is the same evidence linked to the defendant."134 Thus, the
general rule in Maryland is essentially identical with the standard
used in Virginia. Unfortunately, however, Maryland appellate courts
have yet to address chain of custody procedures specifically with
regard to photographic evidence or the related subject of chain of
custody requirements with regard to the transmittal of evidence
through the U.S. mail.
Although Maryland case law provides only limited guidance as
to the required film/photograph handling procedures, additional
insight is provided by a Maryland statute that establishes specific
chain of custody rules for controlled dangerous. substances. 135
Under these rules, the following procedures are followed to
establish that physical evidence constitutes a particular
controlled dangerous sub-stance:
A report signed by the chemist performing the test is
submitted in court that (1) confirms that the chemist is
certified as qualified to analyze controlled dangerous
substances, (2) states that he or she made the analysis under
the procedures approved by the department, and (3) states that
in his or her opinion the substance is or contains the
particular controlled dangerous substance specified.
A statement containing a sufficient description of the
material or its container to identify the material is signed
by each successive person in the chain of custody (defined as
the seizing officer, the packaging officer, the chemist, and
any other person who actually touched the substance when it
was not contained in a sealed package) stating that the person
delivered it to the other person indicated, on or about the
date indicated.
The report and these statements serve as prima facie evidence
that the material delivered to the chemist was properly tested
under the approved procedures, that these procedures are
legally reliable, that the material was delivered to him or
her by the person stated in the report, that the material was
or contained the substance therein reported, and that each
person had custody and made delivery as stated.
The chemist and the successive custodians need not appear in
court to create these prima facie presumptions.
21
Finally, the prosecution can demand (in writing, at least 5
days in advance) the presence of the chemist or any person in
the chain of custody as a prosecution witness at trial.
The statutory rules established for handling controlled
dangerous substances are helpful in determining the film/photograph
handling chain of custody rules since Maryland courts are likely to
follow them, at least to the extent that they agree with the
general common law rule. Thus, for example, it is likely that chain
of custody testimony will not be required by couriersl36 and that
signed statements will suffice (without a court appearance) for
creating a prima facie presumption that the evidence is genuine.
Additional insight is provided by examining the chain of
custody procedures Maryland police officers use to comply with
these rules. In Thompson v. State of Maryland, 137 the procedures
used by the City of Baltimore Police Department are given as
follows. The police officers immediately transport seized
controlled dangerous substances to the evidence control section at
police headquarters. The transporting officer executes a chain of
custody evidence submission form and a property slip detailing the
items submitted for analysis. A technician photographs the evidence
in the presence of the transporting officer, places the items in a
sealed container, and deposits the container in a depository safe
pending chemical analysis. The chemist analyzing the material
records the date he or she received the material, the results of
the analysis, and the date the material is returned to the property
control section. 138
One final indicator of the chain of custody requirements
Maryland courts are likely to impose is the procedure used by the
Maryland Department of State Police for the handling and processing
of photographs admitted into court. According to Lt. Vernon Betkey,
when a state trooper takes a photograph, he or she fills out a slip
that lists the date, time, and location at which the picture was
taken and identifies the photographer. This slip and the film are
then sent to the crime laboratory for processing. The pictures are
returned to the police officer who had them taken and are put in
the case file. Thus, normal chain of custody procedures (such as
evidence bags and custody sheets) are not employed with photographs
(although they are with videotapes) in Maryland.
Privacy Concerns
The film/photograph handling procedures must also ensure that
the privacy rights of individuals photographed while speeding are
not violated. In general,. an individual's right to privacy
originates from three distinct sources: the U.S. Constitution,
state statutory enactments, and state common law court decisions.
As discussed earlier, however, the constitutional right to privacy
applies only to fundamental rights that involve the family sphere,
such as marriage, procreation, and contraception use; it does not
encompass the use of photographs taken on public roads. Thus, any
privacy protection that affects photo-radar operational procedures
must originate from state statutes or case law.
In Virginia, the only statutory protection available to
individuals against governmental privacy invasion are the
restrictions imposed by the Privacy Protection
22
Act of 1976.139 Under this act, agencies and political subdivisions
of the Commonwealth that collect personal information must adhere
to the following guidelines140 to ensure that individual privacy is
safeguarded:
1. The existence of the information system cannot be secret.
2. The need for the information must be clearly established in
advance.
3. The information must be relevant to the purpose for which it
is collected.
4. The information cannot be collected by fraudulent or unfair
means.
5. Information can be collected only as explicitly or implicitly
authorized by law.
6. The information's reliability must be assured, and its misuse
prevented.
7. Clearly prescribed procedures must be in place to ensure that
the information is used only for the purpose for which it was
collected.
For the most part, these guidelines will have little impact on
photo-radar use or on the operational procedures developed for
film/photograph handling.
Examining each of these guidelines in turn, it is apparent
that, with the exception of guidelines 6 and 7, photo-radar use
should not be affected since:
1. The existence of photo-radar photograph files will not be
secret.
2. The need to retain photographs is clearly required given the
potential for court challenges of speeding citations.
3. The retention of photographs clearly meets the purpose of
defending speeding citation challenges in court.
4. Fraudulent or unfair means will not be used to obtain the
photographs.
5. Collection of the information is implicitly authorized by Va.
Code Ann. Section 15.1-138, which authorizes police
enforcement of Virginia's traffic laws, and would be
explicitly authorized by legislation necessary to establish
the photo-radar speed enforcement program.
Guidelines 6 and 7, however, will affect photo-radar
film/photograph handing procedures. Specifically, they will require
that (1) the chain of custody procedures ensure the accuracy and
reliability of the photographs and prevent their misuse, and (2)
that the procedures clearly enjoin use of the photographs for any
purposes other than identify violators and defending ticket
challenges.
Additional statutory privacy constraints are provided by Va.
Code Ann. Section 2.1-380. This section establishes strict
requirements on agencies maintaining information systems containing
personal information (such as photographs) to ensure that the
information is kept confidential. These requirements state that:
23
1. Only personal information permitted or required by law can be
collected, maintained, used, or disseminated.
2. Personal information is maintained consistent with
confidentiality requirements.
3. Information is not disseminated to other information systems
without the sender specific requirements for security and
usage thereof and without receiving reasonable reassurances
that those requirements will be met.
4. A list is maintained of all persons and organizations having
regular access to the information in the system.
5. A complete record including the identity and purpose of every
access to any personal information in the system (excluding
accesses by personnel of the agency that inputs the data) is
maintained for a period of 3 years or until such time as the
personal information is purged, whichever is shorter.
6. Appropriate safeguards are established to secure the system
from any reasonably foreseeable threat to its security.
Thus the procedures established for the handling of photo-
radar film and photographs must also ensure that these constraints
are met.
Privacy constraints arising through Virginia common law court
decisions must also be examined. A review of Virginia case law,
however, reveals that common law privacy rights are unlikely to
affect photo-radar film/photograph handling procedures. Although
Virginia courts have never specifically addressed the privacy
issues involved with governmental photographing of automobile
occupants on public roadways, they have established that (1) a
police officer has the right to look into the interior of an
automobile from any number of angles without compromising any
expectations of privacy that the driver could reasonably have
(since a private citizen could readily make the same
observations),14' and (2) a passenger in a stolen rental vehicle
has no reasonable expectation of privacy in the vehicle.142
Although neither of these decisions is directly on point, they do
indicate a reluctance to find privacy rights with regard to
automobile contents that are in plain view. In addition, although
no Virginia state court has addressed the issue, the Fourth U.S.
Circuit Court of Appeals has held that no common law right of
privacy exists in Virginia, only the statutory right of privacy
discussed previously. 143 Finally, state courts in other
jurisdictions that have addressed the automobile occupant privacy
issue, as well as the U.S. Supreme Court, have been unanimous in
holding that no reasonable expectation of privacy exists when the
automobile is exposed to the public. 144 Given this, it is highly
unlikely that Virginia courts win find that privacy concerns
require special treatment of the film and photographs beyond that
required by statute.
In Maryland, even fewer privacy concerns will affect the
film/photograph handling procedures. The only Maryland statute
affording privacy protection is
24
Md. State Govt. Code Ann. Section 10-618(f), which allows
custodians of public records to deny public inspection of records
of investigations compiled for any law enforcement, judicial,
correctional, or prosecution purpose. Such a denial, however, can
be only to the extent that the inspection would (1) interfere with
a valid law enforcement proceeding, (2) deprive another person of
his or her right to a fair trial, (3) constitute an unwarranted
invasion of personal privacy, or (6) prejudice an investigation. It
is at least conceivable that a Maryland court could find disclosure
of photo-radar photographs to be an invasion of personal privacy,
and thus Maryland officials should not disclose them to the public
unless required to do so by a court order. However, this section
does not in any way restrict the state from taking such
photographs. Thus, as in Virginia, Maryland statutory law will not
require any significant privacy-induced constraints on the photo-
radar procedures.
Maryland common law privacy rights are also unlikely to pose
any constraints on the film handling procedures. Although Maryland
courts have never specifically addressed the privacy issues
involved with governmental photographing of automobile occupants on
public highways, several decisions come fairly close to addressing
this issue and make clear the common law rule in Maryland. In
Fowler v. State of Maryland, 145 a Maryland appellate court held
that "society does not consider the interior of an automobile
parked in a public place to be a place where a person has a
reasonable expectation of privacy."146 Similarly, in Dept of Trans-
portation, Motor Vehicle Administration v. Armacost,147 another
Maryland appellate court held in an automobile context (involving
emission inspections) that 'an individual has no expectation of
privacy in items that he knowingly exposes to the public."48 These
decisions clearly indicate that Maryland courts are opposed to
finding privacy rights with the regard to automobile contents that
are in plain view.
Recommended Procedures
The discussion shows that Virginia and Maryland have similar,
but not identical, rules concerning chain of custody and privacy.
These rules are sufficiently similar so that a single set of
procedures is recommended for the handling of film and photographs
in both jurisdictions. These recommended procedures should satisfy
chain of custody and privacy requirements in both jurisdictions:
In contracts with the camera providers, there should be a
clause ensuring that company representatives will be available
to testify at photo-radar trials as to the installation and
triggering operation of the camera.
In the contract with the company that maintains the cameras,
there should be a clause that ensures that a company
representative will be available to testify at photo-radar
trials as to the periodic testing and maintenance of the
cameras.
Photo-radar cameras should be inaccessible to everyone except
the maintenance personnel and individuals who remove and
replace the film.
A custody sheet should be initiated with each roll of film at
the time the film is placed in the camera. The sheet should
record the dates and times
25
that custody of the film was transferred, as well as the identity
and signature of each transferee.
The film should be either hand delivered or mailed to the
processing laboratory. If mailed, the film should be in a
sealed package. The laboratory technician should verify that
no tampering occurred during mailing.
After processing, prints developed from the film negatives
should be sent in a sealed package to the individuals who
process the citations. The individuals should verify that no
tampering occurred during mailing.
All persons who obtain possession of the film or photographs
should be available to testify at trial.
All persons taking possession of the film should sign and date
the custody sheet, and the film should be stored in a limited
access area when it is not in the physical possession of one
of the custodians to ensure there is no possibility of
tampering.
Negatives should be kept on file at the police photo
laboratory for 1 year so as to ensure their accessibility if
problems develop with the chain of custody of the photographs.
Use of the film or photographs for any purpose other than
identifying violators and defending ticket challenges should
be clearly prohibited.
Negatives and prints should be destroyed periodically after
citations are paid and they are no longer required.
FCC Policy on Photo-Radar
The Federal Communications Commission (FCC) promulgates
guidelines that manage and control radio-frequency use in the
United States. Thus, a potential concern with photo-radar is
whether or not its use is consistent with these guidelines.
Although the photo-radar emitter is essentially identical with FCC-
approved police radar units, concerns regarding photo-radar
compliance with FCC regulations have arisen.
In order to determine whether the use of photo-radar complies
with existing FCC guidelines, Mr. Eugene Thompson of the FCC's
Rules and Regulations Bureau was contacted on May 21, 1992.149 Mr.
Thompson confirmed that the use of photoradar units by law
enforcement agencies (in attended or unattended modes) was con-
sistent with FCC guidelines, and thus, special permission (or
policy waivers) would not be required prior to the implementation
of photo-radar programs.
26
METHODS
Since the use of photo-radar is a complex, multifaceted issue,
the feasibility of its use on the Beltway must be judged based on a
number of criteria, each involving a different aspect of the
technology or its interpretation by the courts. For these reasons,
the method used in this evaluation addressed the following issues:
1. the capabilities of the various models of photo-radar
equipment as noted by manufacturers' claims and demonstrations
at their factory
2. the accuracy of the equipment in determining speeds
3. the reliability of the speed measurements
4. the quality of the photo-radar photographs in terms of the
identification of vehicles and drivers according to legal
specifications
5. the likelihood of successfully detecting and photographing a
speeding vehicle given the obstructions inherent in high-
volume traffic and the difficulty in photographing high-speed
vehicles
6. the effect of photo-radar as used in this evaluation (without
citations) on speed characteristics (i.e., mean speed, 85th
percentile speed, and speed variance)
7. the characteristics of a facility that would affect the
successful use of photo-radar, such as number of lanes
8. the likelihood of detection by standard radar detectors
Site Visits and Manufacturers' Nonempirical Demonstrations
In order to connect information on the various manufacturers
and their photo-radar devices and peripherals, the study team made
two sets of site visits, one in the United States and the other in
Europe. The site visits to Pasadena, California, and Paradise
Valley, Arizona, took place between February 26 and March 5, 1990.
The site visits to Europe were conducted between May 20 and June 2,
1990 (see Table 1). The purposes for these site visits were:
1. To discuss the equipment on site with the manufacturers. The
individuals who know the most about photo-radar equipment are
the individuals who initially developed and now produce the
devices-the manufacturers themselves. However, in many cases,
the manufacturers, especially those located overseas, contract
with agents in the United States to market their products. In
many cases, these agents have very little technical training
)ut are, rat her, experts in sales and distribution. During
the demonstrations, inaccurate information concerning the
equipment was often received from agents who represented the
manufacturers and may not have had the
27
Click HERE for graphic.
28
Click HERE for graphic.
technical expertise or familiarity to be able to provide
answers to technical questions. By dealing with manufacturers
directly, the study team was able to ascertain the
capabilities and idiosyncrasies of the equipment. In addition,
they were able to ensure that the manufacturers were fully
aware of the Virginia/Maryland demonstrations and the testing
criteria for those demonstrations.
29
2. To observe the photo-radar equipment in use at locations where
the manufacturer felt its use had been successful. The study
team believed that the manufacturer would be the best source
of information concerning "successful" use of their products.
In addition, by visiting the photo-radar sites, the team was
often able to discuss the equipment with the technicians
operating it and with police officers who worked the sites.
3. To evaluate the equipments' design and the manufacturers'
claims in relation to photo-radar use on high-density urban
expressways. Most of the locations at which photo-radar has
been used successfully are on city streets and in residential
areas, both of which are very different from a high-volume,
high-speed expressway like the Beltway. During the interviews,
the team members made notes of problems that might affect
Beltway use, such as "screening." (Screening occurs when a
vehicle blocks the radar signal returning from a speeding
vehicle or blocks the camera's view of the vehicle. In these
cases, photo-radar cannot be successfully used.) The study
team made note of this and other problems that might arise on
the Beltway so that the U.S. demonstration phase of the
project could be designed to test for these problems.
Field Demonstrations
During the summer of 1990, five manufacturers of photo-radar
equipment demonstrated their device on interstate highways in
Virginia and Maryland for 2 weeks each. A sixth, Multanova, was
invited to participate in the demonstrations, but declined. Many
steps were taken to ensure a fair and equitable analysis of each
company. During each 2-week study period, the manufacturers were
given the opportunity to take as many pictures as they wished,
using their choice of photographic equipment and film.
Manufacturers were also encouraged to take photographs using their
equipment in as many ways as possible so that each capability of
the equipment could be evaluated. Whenever possible, the film was
developed by a local commercial laboratory. However, when local
processing was unavailable for unusual film types or unusual
canister sizes, other arrangements were made.
All demonstrations were conducted with the manufacturers or
their agents operating the equipment under the constant supervision
of the research team, who collected the data for all tests.
Although the same tests were run for all pieces of equipment, there
were some differences in the manufacturers' experience in operating
their device. For the most part, these were based on the
manufacturers' schedules, their familiarity with the equipment, and
whether all of the equipment's functions were working at the time
of the demonstrations.
There were, however, some conditions under which all of the
manufacturers operated that may have affected the performance of
their device, such as the suitability of permanent loop stations
(and, thus, the study sites) for taking perfect photographs. In
these instances, since all manufacturers operated under the same
conditions, no one manufacturer had an advantage over the others.
30
The performance of each piece of equipment was evaluated after
several tests were conducted at the preselected sites. In order to
prevent biasing of the desired information, the same types of
demonstrations were performed for each type of equipment at the
same sites, on the same workdays, and at approximately the same
time of day.
Site Selection
A major objective of this study was to determine how the
prevailing traffic and geometric conditions at a given site affect
the accuracy of the speeds recorded and the clarity of the
resulting photographs. The ideal location for collecting the
information to evaluate this effectiveness would be where accurate
volume and speed data could be collected and where light conditions
are nearly ideal for photography. The only sites at which speed and
volume data could be collected were at sites where loop sensors
were permanently installed. Unfortunately, these locations were not
necessarily the best for photography. Since the photographs could
be taken at the loop sensor locations, and since it would be
virtually impossible to collect speeds and volumes accurately at
high-volume locations without loops, it was decided that the first
criterion for selecting a site would be the availability of loop
sensors at the site. The next requirement was that the site provide
safe conditions for manufacturers, their agents, and those involved
in collecting the data. The final criterion was that the site be a
two-, three-, or four-lane interstate highway with suitable
vertical and horizontal -alignments. Factors taken into
consideration in evaluating how safe a particular location was
included the availability of adequate site distance and adequate
space away from the edge of the pavement for vehicles and
equipment.
In addition, the conditions at several of the sites
necessitated that equipment be set up in concentrations that may
not have been ideal for photo-radar operation. In Northern
Virginia, for instance, each piece of equipment had to be set
rather far back from the roadway in order to ensure the safety of
the public and the study team, due to the high volumes and high
speeds at these sites. This added an approximate width of one lane
to the distance between the equipment and the target vehicles.
Also, at the I-495 site in Virginia, there was a significant drop
from the roadway to the shoulder that resulted in vehicle-mounted
equipment being tilted by up to 5 degrees. Thus, at this site,
vehicle-mounted units may in some cases have been projecting the
radar beam over compact cars and shooting photographs at an angle.
These operational requirements, although not ideal for the use of
photo-radar, were equivalent for all manufacturers, thereby giving
none an advantage over the others.
The sites selected were therefore not necessarily the most
ideal locations for photo-radar equipment with respect to the
quality of the photographs taken but were the most suitable if all
selection criteria were considered. Thus, it is quite likely that
the photographs taken did not represent the best quality that could
be obtained by the equipment; however, they served as a good means
of comparing the photographic capability between brands of
equipment. Because of the safety criterion used for locating the
study sites, it was not necessary to use any special traffic
control. The traffic pattern was therefore not affected at any of
the study sites.
31
Site Description
After considerable field evaluation of different sites with
loop detectors, six sites were selected based on the enumerated
criteria. Table 2 shows the locations of the test sites and the
traffic and geometric characteristics at each site. Unfortunately,
the ambient lighting conditions were not perfect for photography
throughout the day at each site. For example, according to the
field notes taken by the supervising technician, because of the
angle of the sun, Site 1 was not ideal for photography during the
morning hours but seemed to be much better in the afternoon, and
the lighting conditions at Site 2 were not perfect for photography
in the afternoon. Similarly, the lighting conditions at Sites 4 and
6 seemed better in the morning than in the afternoon, whereas
conditions seemed better in the afternoon at Sites 3 and 5. These
were, however, subjective judgments made at study sites, rather
than empirically based findings.
Photographic Quality and Utility
In order for a photo-radar program to run successfully, the
equipment must be used in such a manner as to produce clear
pictures of speeding vehicles and, if necessary, their driver. To
determine which manufacturers produce the highest quality and most
usable photographs, an analysis of each photograph produced during
the 2-week field demonstration period was conducted.
Due to the large number of photographs taken during each test
period (more than 7,600 total) and the careful scrutiny given each
photograph, the full evaluation of the photographs took about 5
weeks. Detailed information concerning each photograph taken was
entered into a computerized data set as the photograph was being
viewed. The specific variables used in the evaluation of each
photograph were:
1. manufacturer's name
2. roll identification number
3. date the film was exposed
4. time the film was exposed
5. location where the film was exposed
6. conditions under which the film was exposed (i.e., no
problems, problems with equipment itself, problems with setup
of equipment, problems with equipment itself and setup of
equipment, or problems with computer information strip on
picture)
7. direction of traffic photographed (oncoming vs. receding)
8. mode (stationary vs. mobile)
9. weather conditions when film was exposed (i.e., bright sun,
hazy sun, overcast, nighttime, or raining)
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Click HERE for graphic.
10. whether prints or negatives were evaluated
11. number of vehicles in the frame
12. type of vehicle (i.e., passenger car, van/small truck, large
truck or bus)
13. lane in which the vehicle was traveling
14. location of the vehicle in the picture (i.e., no vehicle in
frame, out of range left, in left third of frame, in center of
frame, in right third of frame, or out of range right)
15. whether the license plate could be read
16. reason the vehicle's license plate(s) could not be read (i.e.,
rain, glare, out of frame, too far away, view obstructed, no
plate, reflectorization, or poor film exposure)
17. whether the driver was identifiable as compared to a standard
photograph
18. reason the driver could not be identified (i.e., rain, glare,
out of frame, too far away, view obstructed, receding traffic,
or poor film exposure)
19. whether it was possible to determine which vehicle was
speeding (In cases where two or more vehicles were
photographed, a method was needed to determine which vehicle
had triggered the photo-radar photograph. If a method was
specified and it identified a vehicle in the photograph, this
variable was coded as a "yes.")
Information from each vehicle photographed was then analyzed
to determine what percentage of a manufacturer's pictures could be
used in court, based on possible criteria for photo-radar cases.
These criteria included (1) whether the license plate and the state
of issue were readable, (2) whether the driver could be identified,
(3) whether the vehicle's speed was clearly stated, and (4) whether
the speeding vehicle could be identified in multi-vehicle
photographs. In order to determine which vehicle in a multi-vehicle
photograph was speeding, several manufacturers provided a template.
This clear plastic overlay outlined where in the photograph the
radar beam fell. The vehicle over which the template's radar beam
falls is the speeding vehicle. An additional manufacturer stated
that each template must be drawn based on the speed data for the
particular site. Thus, each site would have its own template. In
cases where there were two or more vehicles in the beam, some
manufacturers claimed that their unit would not take a picture.
Other manufacturers stated that their unit would take a picture but
that such a picture would obviously not be used in a prosecution.
The effect of such factors as weather and distance from the
camera on photographic quality was also evaluated. In addition, at
the start of the evaluation, photographic standards for overall
utility of the photographs were set, against which each
manufacturer's photographs were compared. These standard
photographs appear in Appendix A. Several of the photographs were
enlarged to determine whether
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higher-quality photographs could be produced for use in court. Two
types of film were evaluated: prints and negatives. The prints were
viewed without any enhancements except magnification. The negatives
were evaluated by use of a viewer capable of changing a negative to
a positive image. The FOTOVEK U, a video-based viewing system,
allowed for the adjustment of contrast and focus and enabled the
analyst to magnify specific portions of the negative.
Accuracy of Recorded Speeds
The objectives of this test were to determine the relative
accuracy of the speeds recorded by each piece of equipment and
determine whether the accuracy was significantly affected by the
prevailing traffic and geometric conditions. The tests were carried
out at Sites 1, 2, and 3. No attempt was made to conduct these
tests on the Beltway because it required isolation of the test
vehicles from other vehicles, a practice that is difficult and
could be unsafe in high-volume, high-speed traffic.
Three test vehicles, a Chevrolet Cavalier, a Plymouth Minivan,
and a larger Ford Aerostar Van, were used in this test. The
speedometer of each vehicle was calibrated prior to testing. A
driver was then selected for each vehicle and specifically trained
to drive that vehicle at the required constant speed as the vehicle
traversed the loops at a given site. The training required that
numerous runs be made by each driver until he or she could isolate
the target vehicle from other traffic and could attain the required
velocity at a location about 150 feet from the loops, maintaining
the constant speed as the vehicle traversed the loops. Each driver
comfortably demonstrated his or her ability to meet the test
requirements.
The next stage was to ascertain whether the speeds recorded by
the loops were accurate. This was achieved by having each test
driver isolate his or her vehicle from other vehicles on the
highway and then drive the test vehicle at a given speed across the
loops while being monitored by standard police radar. This
facilitated the clear-cut identification of the speed of the
vehicle as computed by a Streeter-Amet counter connected to the
loops and comparison with police radar. Prior to each test, at
least five runs were made on each lane by each vehicle for speeds
of 40, 50, 55, and 65 mph. (It was not feasible to perform this
test at speeds higher than 65 mph because of the existing maximum
speed limit.) For each run, the speed of the test vehicle was
recorded using standard police radar and was compared to the speed
computed by the Streeter-Amet counter. The lane in which the test
vehicle was driven was also recorded. In a few cases, loop speeds
for several of the 20 or more runs were off by more than 1 mph and
were recalibrated by VDOT personnel. Having ascertained that the
vehicle's speed as measured by police radar and that computed by a
Streeter-Amet counter were within 1 mph of each other, the test to
determine the accuracy of the photo-radar equipment in recording
the speed of an individual vehicle was conducted.
The relative accuracy of the photo-radar equipment was
determined by comparing loop speeds to photo-radar speeds. The
threshold speed of the photo-radar was set at 30 mph so that the
speed of each vehicle passing through its beam could be recorded
and its photograph taken. Each test vehicle was then driven at a
constant
35
speed through the test site, isolating it from the other vehicles.
The test was run for speeds of 40, 50, 55, and 65 mph for each lane
and for each vehicle. For every run, the type of test vehicle, the
speed at which the test vehicle was driven, the speed recorded by
the Streeter-Amet counter, and the speed computed by the photo-
radar equipment were recorded. The lane in which the test vehicle
was driven was also recorded. The speed recorded by each piece of
equipment was then compared with the actual vehicle speed as
obtained at the loops by the Streeter-Axnet counter. The accuracy
of the photo-radar equipment was determined from the variation
between speed recordings produced by the loops and those produced
by the photo-radar equipment.
The testing was carried out under speed test conditions
as specified in the federal minimum performance specifications for
testing equipment accuracy with respect to temperature and supply
voltage (NHTSA, Model Minimum Performance Specifications for Police
Traffic Radar Devices, Technical Report No. DOT HS 807-415,
Washington, D.C., May 1989). However, rather than the researcher
using a stopwatch to determine the average speed of the vehicle
over a stipulated distance, a nearly instantaneous speed reading
was recorded by both the Streeter-Amet counter located at the loops
and the photo-radar equipment being evaluated. Thus, the speeds
recorded by both the counter and the photo-radar equipment were
obtained at the same location and at the same time and, thus, were
instantaneous (or nearly instantaneous) measurements. This is a
much preferred and more accurate method than comparing the
instantaneous speeds measured by the photo-radar equipment with
"average" speeds calculated by timing the vehicles over the
measured distance since the vehicle's speed would vary over the
distance preceding the photo-radar equipment.
Effect of Vehicle Clustering on Accuracy of Speed Measurements
The objective of this test was to determine the accuracy of
the speed recorded by the photo-radar equipment when vehicles were
being driven in tandem across the loops. This test was, therefore,
a repeat of the speed accuracy test but with the test vehicles in a
paired configuration. This required careful driving on the part of
the study team. In this test, the test vehicles were driven in
different lanes, with either the front of the vehicles being on an
approximately straight line when traversing the loops or with each
succeeding vehicle slightly offset behind the preceding vehicle.
The speeds identified at the loops and by the photo-radar equipment
were then recorded and compared. The results of this test indicate
to what extent the arrival of two or more vehicles within the radar
beam of a piece of photo-radar equipment affects the accuracy of
the speed recorded.
Percentage of Usable Photographs of
Vehicles Exceeding Threshold Speed
This test was conducted at all sites when accuracy testing was
not underway. At each site, the photo-radar equipment being tested
was properly positioned and set at a threshold speed that ensured
that all speeding vehicles traveling on the interstate were
counted. The thresholds were also set so that photographs of
speeding vehicles could be taken continuously for at least 3
minutes before the roll of film had to
36
be changed. The photo-radar operation was then initiated and
allowed to continue for a given time period, ranging from 3 to 15
minutes, depending on the threshold speed, vehicle operating
speeds, traffic flow, and number of exposures available in the film
canister. At sites with a high volume and high operating speed
(e.g., I-495), 5-minute intervals were generally used since it took
about 5 minutes to generate 36 photographs (standard film canister
size) without interruption. The test interval was increased to 10
or 15 minutes when a larger number of exposures was available or
when volume was low. This variation in the test interval was
necessary so that an adequate number of speed violators could be
photographed by the photo-radar equipment. Concurrent speed data
were also collected at the loops using the Streeter Amet counter,
from which the number of vehicles exceeding the speed limit for the
same test period was determined. Two figures were then computed:
(1) the number of photographs in which a vehicle's license plate
number and recorded speed could be clearly identified (as a
percentage of the total number of vehicles exceeding the threshold
speed), and (2) the number of photographs in which a vehicle's
license plate number, the recorded speed, and the driver's face
could be clearly identified (as a percentage of the total number of
vehicles exceeding the threshold speed).
Misalignment Flexibility (Cosine Effect)
The objective of this test was to determine the extent to
which misalignment of the photo-radar equipment affected the speed
recorded by the equipment. It was anticipated that equipment might
be unintentionally misaligned by untrained police officers. Each
piece of equipment was, therefore, set up in the operational mode
but intentionally misaligned from the manufacturer's recommendation
by 2, 4, 6, and 8 degrees. The speed accuracy test was then
repeated. The speeds obtained at the loop sensors by the Streeter-
Amet counter were then compared with those recorded by the photo-
radar devices.
Ease of Detection by Radar Detectors
This test determined the maximum distance at which a
commercially available radar detector could detect the presence of
the photo-radar equipment being tested. The radar detector used
was a Cobra Trapshooter, Model RD2100, manufactured by Dynascan
Corporation, Chicago, Illinois. After the equipment was installed
at the test site, a test vehicle with the radar detector installed
was driven slowly toward the equipment until the microwave
radiation from the equipment being tested was detectable. The
location was marked, and the distance from the equipment was mea-
sured. Each test run was repeated at least five times, and the
maximum detectable range for each manufacturer's photo-radar
recorded.
There are two possible effects a radar detector could have on
the effectiveness of photo-radar use. First, by knowing where
photo-radar devices are located, drivers may avoid citation by
slowing down at the photo-radar site and then speeding up once they
have passed the site. Thus, radar detectors could reduce the
effectiveness of photo-radar in reducing speeds on other sections
of the roadway. On the other hand, radar detection of photo-radar
equipment would, in itself, reduce speeds at the site, one of the
objectives of its use.
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Effect of Photo-Radar on Speed Characteristics
Speed data were collected at each site at least 1 month before
the field demonstration and again during the demonstration. No
citations or warnings were given during the test period, but the
minimal media attention given as a result of the Tuesday press
conferences may have alerted drivers to the presence of the
equipment for testing. This publicity took the form of newspaper
articles and television and radio interviews in which the principle
of photo-radar was described and the reasons for conducting the
demonstration were explained. It was, however, made quite clear to
the public that no citations would be given based on speeds
observed and recorded during the demonstration. As an additional
confounding factor, police consistently worked radar during the
demonstration at Site 6 in Maryland. Since this was their standard
procedure, it was decided that they should continue so the units
could be evaluated under real-world conditions. However, the use of
standard radar during the testing may have affected the speed
characteristics at that site.
The researchers are of the opinion that the true impact of
photo-radar on speed characteristics could not be ascertained from
these results. Then citations and warning letters are given, it is
likely that the impact of photo-radar on speed characteristics,
such as the mean and 85th percentile speeds, will be different from
that reported in this study.
Public Acceptance
In order to assess the potential level of acceptance for
photo-radar use on the Beltway, a telephone survey was conducted.
Core questions for this household-based survey were drawn from
those developed by the Insurance Institute for Highway Safety for
its surveys in Pasadena, California, and Paradise Valley, Arizona
(Freedman, M., Williams, A. E, and Lund, A. K, 1990, "Public
Opinion Regarding Photo-Radar," Transportation Research Record
1270, Transportation Research Board, Washington, D.C.). Obviously,
only those questions that apply to potential use of the equipment,
rather than actual use, were included in the questionnaire (see
Appendix B).
The survey population consisted of all households with a valid
telephone number in the Washington metropolitan area. Random-digit
dialing techniques were used, and all interviews were computer
assisted. The sample was stratified by sex and location such that
(1) 55 percent of the respondents were male and 45 percent female,
and (2) 45 percent of the sample was drawn from Northern Virginia,
45 percent from Southern Maryland, and 10 percent from Washington,
D.C. This was done to avoid the standard sex bias that often occurs
in telephone surveys (since females answer the telephone more
