Final Report
Model Deployment of a Regional,
Multi-Modal 511 Traveler Information System
Multi-Modal 511 Traveler Information System
Appendix A
Background on the Highway Condition and Reporting System
The subject matter of HCRS event entries is characterized using International Traveler Information Interchange Standard (ITIS) "category" and "description" information. There are 22 different ITIS categories in all, and each ITIS category includes anywhere from a few to several hundred specific messages or "descriptions." There are a total of 1,374 ITIS descriptions. The table below lists the ITIS categories and a couple of ITIS description examples from each category.
| ITIS Categories | Examples of Associated ITIS Descriptions |
|---|---|
| Level of Service | Stop and go traffic for 3 miles Expect Traffic Congestion |
| Incidents/Accidents | Disabled vehicle. Delays Overturned vehicle |
| Closures | Road blocked ahead. Long delays On- and off-ramps blocked |
| Lane Restrictions | Narrow lanes. Expect slow traffic Right lane closed |
| Road Maintenance | Road marking operations. Two lanes closed Road construction. Heavy traffic. |
| Obstruction Hazards | Object on roadway Flooding. Expect heavy traffic. |
| Road Conditions | Fuel on roadway Loose gravel. Caution |
| Weather | Rain. Visibility reduced. Partly cloudy weather |
| Winds | Tornado watch Strong winds |
| Environment | Sandstorms Patchy fog |
| Activities | Sports event. Traffic building up Closed due to parade |
| Delays/Cancellations | Delays for buses. Irregular service Delays up to 20 minutes |
| Dangerous Vehicles | Objects falling from moving vehicle High-speed chase |
| Exceptional Loads | Wide load Military convoy |
| Traffic Equipment Status | Traffic lights working incorrectly. Delays Railroad crossing failure. Slow traffic |
| Traffic Regulations | Police directing traffic Temporary axle load limit |
| Headways | 30 minute headway 5 minute headway |
| Travel Times | 5 minute travel time 20 minute travel time |
| Parking | No parking Parking garage full |
| Information | Gas station closed Rest area closed |
| Winter Storm Codes | Ice Winter storm advisory |
As an example, the following message was the sixth of eight messages for I-10, at 2:00 p.m. on Wednesday, October 29, 2003:
"Height limit 16 feet 5 inches, width limit 24 feet, east and westbound from 22nd Street to 6th Avenue. Roadway reduced to two lanes.
Expect slow traffic. Until July 31, 2004."
This message was generated by an event entry that utilized the "Lane Restriction" ITIS category, description #561: "Roadway reduced to two lanes. Expect slow traffic." The height and width limit and schedule information were pulled from other parts of the HCRS event entry form (in addition to specifying ITIS categories and descriptions other information, including restrictions, can be added to each event).
