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TRANSIMS Model Design Criteria as Derived from Federal Legislation
Click HERE for graphic. June 12, 1995 LAUR 95-1909 TRANSIMS Model Design Criteria as Derived From Federal Legislation Jack Morrison and Verne Loose Executive Summary TRANSIMS design needs are influenced by assessments by the professional transportation community that the recent Intermodal Surface Transportation Act (ISTEA) and Clean Air Act Amendments (CAAA) generate analytical requirements that exceed the capabilities of current models and methodologies. ISTEA defines an integrated state and metropolitan planning and management system that requires a family of programmatic, planning, management, and data collection documents to insure compliance with federal standards. The CAAA establishes revised attainment standards for 4 transportation-related pollutants and their precursors as well as a strengthening of conformity provisions. New conformity determination standards will require transportation planners to prepare long-range demand forecasts and to conduct air quality modeling with sufficient fidelity to predict absolute levels of pollution as a function of increased travel demand as well as changes to the regional transportation system. TRANSIMS will provide an analytical environment within which state and local planners can meet these and other analysis requirements. In order to be locally adaptable, this environment must incorporate basic functional representations that can be readily and easily applied to data characterizing the local environment to form a complete rep- resentation of the objective region. To achieve these general objectives, TRANSIMS must represent: - the land use and demographic characteristics of different regions; - the natural environment associated with that domain; - an multimodal transportation network; - representative populations and commercial environments; - the unique travel decisions of individuals; - detailed vehicle representations; - the detailed dynamics of regional traffic; and - the unique influences of traffic on congestion and air quality. Key representational requirements are: entity-level representation of individual travelers and freight items; representation of relatively sophisticated behavior including choice/utility models; travel and environmental models, system simulations, and component models that are sensitive to relatively detailed representations of environmental and vehicle characteristics; and simulation of continuous traffic, transit, freight, bike, and pedestrian travel patterns over the course of an extended period (incorporating both peak and non-peak travel demand), as well as different days of the week, months, and seasons. 1 Table of Contents 1.0 Table of Contents 3.0 Introduction. . . . . . . . . . . . . . . . . . . . . . . 3 4.0 High Level Requirements . . . . . . . . . . . . . . . . . 3 4.1 Motivation. . . . . . . . . . . . . . . . . . . . . . 3 4.2 System Perspective. . . . . . . . . . . . . . . . . . 4 5.0 Intermodal Surface Transportation Efficiency Act. . . . . 6 5.1 Purpose of ISTEA. . . . . . . . . . . . . . . . . . 6 5.2 Synopsis of the ISTEA . . . . . . . . . . . . . . . 6 5.2.1 Title I (Surface Transportation) . . . . . . . . 7 5.2.2 Title II (Highway Safety). . . . . . . . . . . . 8 5.2.3 Title III (Federal Transit Act Amendments) . . . 8 5.2.4 Title IV (Motor Carrier Act) . . . . . . . . . . 8 5.2.5 Title V (Intermodal Transportation). . . . . . . 8 5.3 Statewide Transportation Planning . . . . . . . . . 8 5.4 Transportation Improvement Program. . . . . . . . . 9 5.5 Transportation Plan . . . . . . . . . . . . . . . .10 5.6 Statewide Transportation Management System. . . . .11 5.6.1 Introduction . . . . . . . . . . . . . . . . . .11 5.6.2 State and TMA Congestion Management Systems (CMS). . . . . . . . . . . . . . . . . .12 5.6.3 State Highway Safety Management System (SMS) . .12 5.6.4 State Public Transportation Management System (PTMS). . . . . . . . . . . . . . . . . .13 5.6.5 State Intermodal Management System (IMS) . . . .13 5.6.6 Traffic Monitoring System (TMS). . . . . . . . .14 6.0 Clean Air Act Amendment . . . . . . . . . . . . . . . . .15 6.1 Synopsis of the Clean Air Act Amendments (CAAA). 15 6.1.1 Title I (Attainment and Maintenance of NAAQS). . . . . .15 6.1.2 Title II (Emissions Standards for Mobile Sources) . . . .16 6.2 Introduction. . . . . . . . . . . . . . . . . . . .16 6.3 State Implementation Plan (SIP) . . . . . . . . . .17 6.4 Conformity Criteria . . . . . . . . . . . . . . . .18 7.0 Analysis Requirements . . . . . . . . . . . . . . . . . .19 7.1 Transportation Management Analysis Requirements . .19 7.1.1 Major Investment Studies . . . . . . . . . . . .19 7.1.2 Methodology. . . . . . . . . . . . . . . . . . .19 7.2 Air Quality Analysis Requirements . . . . . . . . .19 7.2.1 Air Quality Studies. . . . . . . . . . . . . . .19 7.2.2 Analytical Approach. . . . . . . . . . . . . . .20 7.2.3 Models . . . . . . . . . . . . . . . . . . . . .20 7.2.4 Measures of Performance (Sensitivities). . . . .21 8.0 Derived Functional Requirements for TRANSIMS. . . . . . .22 8.1 Overview. . . . . . . . . . . . . . . . . . . . . . .22 8.2 Component Requirements. . . . . . . . . . . . . . . .24 8.2.1 Transportation System Data Component . . . . . .24 8.2.2 Transportation Simulation Component. . . . . . .27 9.0 Definitions, Acronyms, and Abbreviations. . . . . . . . .32 10.0 References 33 2 TRANSIMS Model Design Criteria as Derived From Federal Legislation Introduction 2.0 Introduction 2.1 Purpose As the initial step in formalizing the TRANSIMS design, this paper translates our interpretation of the analytical needs that are explicitly or implicitly derived from recent federal legislation into high-level simulation design. Although some development work has begun, this document is not a description of TRANSIMS. Rather, it communicates the team's understanding of the most likely federal policy environment within which TRANSIMS will be applied. This document, therefore, serves as a basis for feedback from the user community regarding the overall objectives of the simulation environ- ment. It should be noted that the project and design are motivated by a broad need to enhance the analytical capabilities of the transportation community and are, therefore, not exclusively influenced by the recent federal legislation cited in this document. 2.2 Scope This document is broad in scope to address the entire policy domain that an integrated simulation framework must embrace. It is focused at a level that it can be readily understood by persons who may not be simulation subject matter experts. 2.3 Audience This document is directed at metropolitan planning office personnel, federal and state department of transportation and air quality personnel, municipal and county planners and other stakeholders in the air quality and transportation planning communities. Additional stakeholders include the environmental community, firms that provide services to the urban transportation planning community, and the general public. 3.0 High Level Requirements 3.1 Motivation TRANSIMS design requirements are significantly influenced by well- documented assessments by the professional transportation community that the recent Intermodal Surface Transportation Act (ISTEA) and Clean Air Act Amendments (CAAA) generate analytical requirements that exceed the capabilities of models and methodologies currently in use. More specifically, state and metropolitan planning organizations will be required to address forecasting issues related to infrastructure, congestion, and air quality in more precise and quantitative terms than have been requited in the past. Additionally, because of the legal ramifications of these federally-mandated requirements, the validity and verification of the embedded models and methodologies will likely come under greater scrutiny than in the past. With respect to transportation planning requirements under ISTEA, the Federal Register [23 CFR Part 500, 2 March -1993] provides this assessment of state and local professionals as well as national interest groups. TRANSIMS Model Design Criteria as Derived From Federal Legislation 3 High Level Requirements [With respect to] the capability of existing transportation planning models and procedures to identify congestion problems and possible corrective strategies and to measure performance of implemented strategies at the micro level. Approximately one-third of the responses, generally from rural States, said the existing tools were adequate. Another third of the responses, primarily from States with a mixed level of, urban development, indicated that existing tools needed to be enhanced. The remaining responses were from highly urbanized States and indicated that existing tools were not adequate and needed to be completely replaced. A recent analysis of air quality modeling capabilities conducted for the National Association of Regional Councils provides an equivalent assessment with respect to CAAA needs. In order to meet CAA requirements, many metropolitan planning organizations (MPOs) will need to monitor growth rates, track vehicle miles of travel, and forecast the impacts of transportation options In more precise and quantitative terms than have been necessary in the past- Regardless of whether major updates of regional models and data bases are deemed necessary, however, many MPOs are finding that the new planning context calls for new approaches to analysis. [Specifically].. the typical regional model is unequipped to handle a plethora of other TCMs, including signal timing, ramp metering, ele- ments of employer-based demand-management programs, many land use and urban design measures, and (sometimes) pricing strategies. 2 3.2 System Perspective Figure 1 represents a top-down view of the policy environment that TRANSIMS must address. The figure illustrates how the existing policy environment for transportation decision-making has been affected by the recent legislative initiatives represented by ISTEA 1991 and the CAAA 1990. The shaded boxes represent the thrust of new legislation and the new requirements that this legislation imposes on the existing system and the principal focus of the current TRANSIMS development program. We now address the affects of this new legislation. _________________ 1 Federal Register, Vol. 58, No. 39, 2 March 1993. 2 Harvey and Deakin, 1992. 4 TRANSIMS Model Design Criteria as Derived From Federal Legislation High Level Requirements FIGURE 1. TRANSIMS Policy Environment Click HERE for graphic. TRANSIMS Model Design Criteria as Derived From Federal Legislation 5 Intermodal Surface Transportation Efficiency 4.0 Intermodal Surface Transportation Efficiency Act 4.1 Purpose of ISTEA Develop a National Intermodal Transportation System that is economically sound, provides the foundation for the Nation to compete in the global economy and will move people and goods in an efficient manner. The overall objective of the ISTEA is the improved performance of statewide and metropolitan transportation systems through: - preservation of existing facilities and equipment; - operational enhancements to improve the efficiency and environmental impact of the system; and, - capacity enhancements to improve the effectiveness of the intermodal system. The Act defines an integrated, two-tier (state and metropolitan) planning and management system that requires the preparation, coordination, approval, and maintenance of a family of programmatic, planning, management, and data collect documents to insure compliance with federal standards intended to sustain these objectives. At both the state and local level, transportation offices are required to maintain: - A Transportation Improvement Program CM of prioritized and supportable transportation projects for near-term (3-year horizon) implementation; - A Transportation Plan that synthesizes local goals and objectives with federally mandated criteria into a long-term plan (20-year horizon); and, Associated with these short- and long-range management documents, states are further required to maintain transportation management systems that support the three objectives of the Act. Further, it is the responsibility of the states and MPOs to insure that transportation plans in general, and surface transportation plans in particular, support national air quality goals, guidelines, and remedial programs as directed under the Clean Air Act Amendment. 4.2 Synopsis of the ISTEA 1991 ISTEA constitutes a landmark in the definition, resourcing, and management of the National Highway System (NHS). This report focuses on Titles I through VI which address intermodal and surface transportation. Titles VII (Air Transportation) and VIII (Extension of Highway-Related Taxes and Highway Trust Fund) are related only indirectly to the TRANSIMS project. Figure 2 highlights those essential elements of ISTEA that are directly relevant to TRANSIMS. 6 TRANSIMS Model Design Criteria as Derived From Federal Legislation Intermodal Surface Transportation Efficiency Act FIGURE 2. Relationship Between ISTEA and TRANSIMS Click HERE for graphic. 4.2.1 Title I (Surface Transportation) This Title focuses on the activities of the Federal Highways Administration (FHWA). Under this Tide, Congress directed that the four previous federal-aid highway systems (Interstate, Primary, Secondary and Urban) be redefined as a single National Highway System (NHS) with a separately defined sub-element, the Interstate System. The 155,000 miles of the NHS-defined roadways constitute roughly 15% of the major roadways in the U.S. Under Title I, Congress apportions separate funds for the NHS ($211B), the Interstate System ($25B), as well as a Surface Transportation Program (STP) ($24B) that provides block grants to the states for both NHS and non-NHS roadways that are not local or rural minor collectors. These funding levels are for a 6-year period. In addition to redefining and resourcing the NHS, Title I of the ISTEA defines a Congestion Mitigation and Air Quality Improvement Program ($6B) as well as federally mandated procedures for state and metropolitan transportation program management. The Congestion Mitigation and Air Quality section of Title I provides funding for transportation projects that have air quality benefits. The federal management requirements stipulate procedures for the management of federally supported transportation projects in terms of federal guidelines for: congestion reduction, safety, public transportation, TRANSIMS Model Design Criteria as Derived From Federal Legislation 7 Intermodal Surface Transportation Efficiency Act intermodalism, pavement and bridge maintenance, and traffic monitoring. This program is a particular focus of this report and is discussed in detail in Section 4. 4.2.2 Title II (Highway Safety) This Title provides funds ($1.6B) and direction to the FHWA and the National Highway Traffic Safety Administration (NHTSA) for a national motor vehicle safety program. These provisions are not relevant to TRANSIMS requirements. 4.2.3 Title III (Federal Transit Act Amendments) This Title renames the Urban Mass Transit Administration the Federal Transit Administration (FTA) and authorizes $31.5B over 6 years for Transit Formula and Discretionary programs. The planning and management of these transit programs as well as the analysis of proposed projects under the federally mandated management systems (Title 1) generate TRANSIMS requirements. 4.2.4 Title IV (Motor Carrier Act) This Title does not directly affect TRANSIMS requirements. 4.2.5 Title V (Intermodal Transportation) This Title provides for a new Office of Intermodalism under the Office of the Secretary of Transportation to coordinate federal research on intermodal transportation. Although this Title does not provide specific requirements for TRANSIMS, it does provide a basis for support of intermodal management systems for the states as mandated under Title I. Although ongoing research programs under Title VI (Research) will not generate high-level requirements for TRANSIMS, they do identify potential future system characteristics that may be incorporated into TRANSIMS design and implementation requirements. In addition, TRANSIMS ultimately should provide an analytical environment within which to support transportation research. 4.3 Statewide Transportation Planning ISTEA explicitly requires that each state develop and implement a state planning process to implement this program. Implicit in this requirement is the responsibility to develop state-specific goals, objectives, measures of merit, and procedures to insure that these programmatic requirements support a coherent, efficient, and effective intermodal management system. TRANSIMS is intended to provide an analytical environment within which state and metropolitan planners can meet these analytical requirements. Figure 3 provides a graphical representation of the basic components of this planning and management system. The figure reflects the role of the State Transportation Plan in integrating six federally mandated management programs (and supporting data collection system) into a long-range, statewide plan. Through periodic review and continual update, these activities provide the basis for the State Transportation Improvement Program (STIP), that is a resource- constrained, prioritized list of the proposed, near-term projects to be supported by federal transportation funds. Figure 3 also shows that each MPO is required to prepare, coordinate, and approve its own Transportation Plan and Improvement Program. Although Congestion Manage- 8 TRANSIMS Model Design Criteria as Derived From Federal Legislation Intermodal Surface Transportation Efficiency Act ment Plans are required for TMAs, MPOs are not otherwise required to maintain formal management plans. However, the majority of the project-specific and emissions analyses that will provide the bases for the statewide management systems will be supported at the metropolitan level. FIGURE 3. Integrated State and Metropolitan Transportation Planning System Click HERE for graphic. 4.4 Transportation Improvement Program The State Transportation Improvement Program (STIP) is a financially constrained, prioritized list of proposed capital and non-capital improvement projects along with the agencies responsible for carrying out each project. The program is financially constrained by anticipated state and federal funds. The planning horizon for the STIP is not less than 3 years. The STIP must be updated and submitted every two years to FHWA and FTA for joint approval. Each MPO will prepare a TIP in coordination with state planning authorities who will provide estimates of available state and federal funds. Following approval by the MPO and the governor, the TIP will be included, without modification, in the STIP. TRANSIMS Model Design Criteria as Derived From Federal Legislation 9 Intermodal Surface Transportation Efficiency Act 4.5 Transportation Plan State and metropolitan transportation plans are continuously updated, long-range planning documents that integrate federal, state and local management and planning activities into a comprehensive set of intermodal plans with the input of 6 federally mandated management systems as well as TCMs stipulated in the SIP. The purpose of these plans is to facilitate the efficient and economic movement of people and goods in the state. The required features of all state and metropolitan plans include: - intermodal planning; - 20-year planning horizon; - coordination and integration of state and local plans; and - reference, summarize or contain relevant planning and management systems input to planning process. Unique requirements for the Metropolitan (and TMA) Transportation Plan are: - review, update and approval by the MPO every: - 3 years in nonattainment and maintenance areas, and - 5 years in attainment areas; - identification of projected transportation demand of persons and goods over the period of the plan; - congestion management strategies including, as appropriate: - traffic operations, - ridesharing, - pedestrian and bicycle facilities, - alternate work schedules, - freight movement options, - high occupancy vehicle treatments, - telecommuting, and - public transportation improvements including: regulatory pricing, management, and operations; and - incorporation of a multimodal evaluation of the transportation, socioeconomic, environmental, and financial impacts of all major investments. These major transportation investment (subarea and corridor) studies are required to evaluate the cost-effectiveness and other aspects of major federally supported problem solutions with respect to local, state, and national goals and objectives. These studies will also provide the analytical basis for demand reduction and operational management studies conducted in support of congestion management plans as well as environmental impact studies. Major investment studies will analyze the direct and indirect costs of reasonable transportation alternatives with respect to: - personal mobility improvements; - social, economic, and environmental affects; - safety; 10 TRANSIMS Model Design Criteria as Derived From Federal Legislation Intermodal Surface Transportation Efficiency Act - operating efficiencies; - land use and economic development; - financing; and, - environmental impacts and energy consumption. Within the context of the complex relationship that links environmental and transportation planning, major investment studies may provide input to environmental studies. In that one of the purpose of TRANSIMS is to provide an analytical environment for these studies, these serve as high-level design requirements for TRANSIMS. 4.6 Statewide Transportation Management System 4.6.1 Introduction ISTEA mandates that, prior to 1995, each state implement 6 management and 1 monitoring system according to the stipulated phase-in schedule in order to focus transportation programs on the three federally- mandated objectives: - Objective: Preservation of existing facilities and equipment Pavement Management System (PMS) Bridge Management System (BMS) Public Transportation Management System (PTMS) Intermodal Management System (IMS) - Objective: Enhancement of system capacity Congestion Management System (CMS), IMS, and PTMS - Objective: Enhancement of operations Safety Management System (SMS), IMS, PTMS, and CMS While not a management system, the Traffic Monitoring System (TMS) is a federally mandated supporting system that provides for the collection and management of field data to support analysis of the traffic aspects of the 6 management systems. In developing their overall transportation management system, the state transportation authorities must coordinate with MPOs and the DOTs Transportation Research Board. Directly relevant to TRANS IMS is the requirement for states to develop and satisfy data requirements to support the 6 management plans as well as to develop measures of performance (MOP) and measures of effectiveness (MOE) suitable for analyzing the behavior of the state transportation system relative to the previously identified objectives. With respect to data requirements, the state must identify a family of collectable data that can: - define and monitor the magnitude of system performance characteristics; - identify needs; - compare alternative solutions; and - measure implementations (confirm design assumptions). This paper does not address the PMS, BMS or aspects of the PTMS and IMS that are strictly associated with preserving existing infrastructure. This report focuses on the analysis requirements associated primarily with CMS, SMS, PTMS, and IMS opera- TRANSIMS Model Design Criteria as Derived From Federal Legislation 11 Intermodal Surface Transportation Efficiency Act tions and capacity as well as the supporting role of the TMS. TRANSIMS will support the requirement to analyze the impact of facility improvement on system capacity. 4.6.2 State and TMA Congestion Management Systems (CMS) The CMS is a systematic process that provides information on transportation system performance and alternative strategies to alleviate congestion and enhance the mobility of persons and goods. A CMS includes methods to monitor and evaluate performance, identify alternative actions, assess and implement cost-effective actions, and evaluate the effectiveness of implemented actions. [CFR Vol. 58, No. 229, p. 644801 The CMS will consist of. continuing assessment of all transportation corridors with existing or potential congestion (defined locally); a data collection and management system for selected performance measures established cooperatively by the state and affected MPOs, local officials and subsystem operators; and, a methodology for evaluating and implementing alternative congestion management strategies. Alternative congestion management strategies will include, but not be limited to: - transportation demand management measures such as car and van- pooling, congestion pricing, alternative work hours, telecommuting, and parking management; - operational improvements such as intersection and roadway widening, addition of general purpose lanes, channelization and access management incident management procedures, traffic surveillance and control systems, motorist information systems, ramp metering, traffic control centers, and computerized signal systems; - measures to encourage high occupancy vehicle (HOV) use such as HOV lanes, HOV ramp bypass lanes, guaranteed ride home programs, and employer trip reduction ordinances; - public transit capital improvements such as exclusive rights-of- way (rail and bus), bus bypass ramps, park and ride as well as mode change facilities, and paratransit facilities; - public transit operational improvements such as service enhancement or expansion, signal preemption, fare reductions, and transit information systems; - measures to encourage the use of nontraditional modes such as bicycle facilities, pedestrian facilities, and ferry service; - growth management and activity center strategies; and, - intelligent transportation system (ITS) and advanced public transportation system technology. ISTEA mandates that a CMS be incorporated into the planning process for all TMAs. When a TMA is classified as nonattainment for ozone and/or carbon monoxide, a CMS is required for the entire metropolitan planning area. These (ozone and CO) nonattainment TMAs must also provide an analysis of all (multimodal) reasonable travel demand reduction and operational management strategies for any highway improvement that will significantly increase SOV capacity. In nonattainment or maintenance areas, the CMS will be carefully coordinated with the SIP as discussed in Section 5. 4.6.3 State Highway Safety Management System (SMS) The SMS is a systematic process that has the goal of reducing the number and severity of traffic crashes by ensuring that all opportunities to improve highway safety are iden- 12 TRANSIMS Model Design Criteria as Derived From Federal Legislation Intermodal Surface Transportation Efficiency Act tified, considered, implemented as appropriate, and evaluated in all phases of highway planning, design, construction, maintenance, and operation and by providing information for selecting and implementing affective highway safety strategies and projects. [CFR Vol. 58, No. 229, p. 63479] While much of the activity mandated for safety management is beyond the scope of TRANSIMS, the SMS requires states to collect and maintain accident, emergency response, and enforcement-related data for analysis of safety issues and proposed countermeasures. In addition, TRANSIMS' explicit treatment of congestion may provide a mechanism for directly or indirectly relating congestion levels to accident prediction as well as the contribution of accident response capabilities to congestion management. 4.6.4 State Public Transportation Management System (PTMS) The PTMS is a systematic process that collects and analyzes information on the condition and cost of transit assets on a continual basis. It identifies needs as inputs to the metropolitan and statewide planning process enabling decisionmakers to select cost effective strategies for providing and maintaining assets in a serviceable condition. [CFR, Vol. 58, No. 229, p. 63482] While maintenance of infrastructure is beyond the scope of TRANSIMS, ISTEA mandates that proposed PTMS strategies and projects shall be evaluated for potential inclusion in state and metropolitan transportation plans and programs especially as they relate to the CMS and IMS. Therefore, state transportation authorities must develop methodologies for analyzing the potential impact of changes in the characteristics of the public transportation subsystem. These subsystem characteristics can include capital and non-capital improvements that affect capacity and operational capabilities. In addition, public transportation vehicles are included in the Traffic Monitoring System that will, therefore, collect relevant subsystem performance data. 4.6.5 State Intermodal Management System (IMS) The IMS is a systematic process of identifying key linkages between one or more modes of transportation, where the performance or use of one mode will affect another, defining strategies for improving the effectiveness of these modal interactions, and evaluation and implementation of these strategies to enhance the overall system performance of the transportation system. [CFR Vol. 58, No. 229, p. 63483] IMS will consist of: an inventory of intermodal facilities and systems; a data collection and management system for selected performance measures; and, a strategy and plan for improving intermodal efficiency. ISTEA directs that the states evaluate alter- native projects with respect to their effect on improving overall intermodal system efficiency. Relevant performance measures include: - trip travel time and cost; - volume of cargo and passengers moved (usage); - available facilities (to include parking as well as pedestrian and bike facilities); - subsystem and system capacity; - accidents / safety; - ease of access; TRANSIMS Model Design Criteria as Derived From Federal Legislation 13 Intermodal Surface Transportation Efficiency Act - mode transfer time, cost, and ease; and, - perceived quality of service. 4.6.6 Traffic Monitoring System (TMS) The TMS is a systematic process for the collection, analysis, summary, and retention of highway-related person and vehicular traffic data, including public transportation on public highways and streets. The state TMS shall be based on the concepts described in the American Association of State Highway and Transportation Officials (AASHTO) "AASHTO Guidelines for Traffic Data Programs," the FHWA "Traffic Monitoring Guide," and the HPMS Field Manual. Components of the state TMS will include: data precision, continuous counter operations, short term traffic monitoring, and vehicle occupancy monitoring. For data precision, the TMS shall meet the standards for statistical precision established by the FHWA for the HPMS. With respect to continuous counter operations, the IMS will provide for estimates of day-of-week, seasonal, axle correction, growth factors and other components required to meet the guidelines established by the FHWA. Short term traffic monitoring shall be adjusted to reflect annual average conditions using appropriate adjustment factors. Vehicle occupancy data will be collected and maintained on the average number of people per automobile, light two axle truck, and bus collected through roadside monitoring, traveler surveys, administrative records, accident reports, public transportation reports or any other method approved by the FHWA. 14 TRANSIMS Model Design Criteria as Derived From Federal Legislation Clean Air Act Amendment 5.0 Clean Air Act Amendment 5.1 Synopsis of the Clean Air Act Amendments (CAAA) Following the Clean Air Act of 1970, emissions of pollutants in general, and those produced by automobiles in particular, were reduced in spite of a 24% increase in vehicle miles of travel (VMT) over the 20 year period. However, by 1988, 101 urban areas continued to exceed National Ambient Air Quality Standards (NAAQS) for ozone and 44 for carbon monoxide (CO). In 1991 Congress passed, and the President signed, a series of amendments to the CAA. The first two tides of the 1990 CAAA strengthened the regulatory guidance associated with the management of air quality standards and established higher standards for mobile source emissions -- cars and trucks. 5.1.1 Title I (Attainment and Maintenance of NAAQS) Title I establishes revised attainment standards for 4 transportation- related pollutants and their precursors: - Ozone (O3); - Carbon Monoxide (CO); - Nitrogen Dioxide; - Particulate Matter of Less Than 10 Microns (PM-10); as well as - Volatile Organic Compounds (VOCs) and Oxides of Nitrogen (NO,) in selected cases. Nonattainment areas are classified according to the extent to which the standards are exceeded -- from marginal to extreme. Nonattainment areas with a more severe status have longer to achieve attainment status but bear more severe external oversight and have the potential for more transportation project restrictions. Title I also strengthens the conformity provisions which ensure that DOT transportation planners incorporate air quality standards in their planning. The 1970 CAA required transportation planners to implement Transportation Control Measures (TCMs) identified in the State (air quality) Implementation Plan (SIP) as being necessary to reduce mobile source emissions in the state and metropolitan plans and programs. The 1990 Title I additions now require transportation planners to determine that all projects, in the aggregate, will not exceed the emissions levels allocated by the SIP. Therefore, plans, programs, and projects must conform to the SIP's purpose to eliminate or reduce the severity and number of violations of the NAAQS and achieve expeditious attainment of the these standards. The complexity and required fidelity of these analyses will depend on the air quality status of the nonattainment areas affected. The new conformity determination standards will further require transportation planners to prepare long-range transportation demand forecasts and to conduct air quality modeling with sufficient fidelity to predict absolute levels of pollution as a function of increased travel demand as well as changes in the design and operation of the regional transportation system. The unprecedented scope of this analytical requirement (regional transportation system performance sensitivity to detailed emissions models) motivated the TRANSIMS project and its specific design requirements. TRANSIMS Model Design Criteria as Derived From Federal Legislation 15 Clean Air Act Amendment 5.1.2 Title II (Emissions Standards for Mobile Sources) This Title establishes more stringent emissions standards for cars and trucks produced between 1996 and 2003. With respect to TRANSIMS, this regulation generates a requirement to incorporate emissions models that are sensitive to engineering design features of cars and trucks. The clean fuels portion of this Title generates an additional modeling requirement sensitivity to alternative fuel sources in a percentage of the modeled vehicles. 5.2 Introduction While the CAAA of 1990 established a number of specific performance standards for nonattainment areas as well as mobile sources, the focus of this document is the analytical procedures associated with supporting the development of TCMs as well as making conformity determinations for transportation projects, plans, and programs as defined under the ISTEA. The air quality regulatory environment is as reflected in Figure 4. TCMs are specific transportation-related projects (capital or operational) associated with achieving required reductions in transportation-related pollutants. When incorporated into the SIP, these TCMs are required to be included and supported in the appropriate state and metropolitan TIN and Plans. Conformity Determinations, conducted and validated by the MPO or State DOT, verify that the TCMs are being implemented, and that all other transportation projects have been evaluated, in the aggregate, to insure that the overall program- FIGURE 4. Conformity Determination Click HERE for graphic. 16 TRANSIMS Model Design Criteria as Derived From Federal Legislation Clean Air Act Amendment 5.3 State Implementation Plan (SIP) Figure 5 reflects the general process by which each state develops the transportation-related input to the SIP. The principal components of this process are: National Ambient Air Quality Standards; projections of regional growth; an emissions analysis; projections of specific pollutants across an emissions budget and milestone and attainment dates; and TCMs and other measures as required to insure future regional transportation conditions are constrained to remain within the prescribed emissions budget. FIGURE 5. SIP Development Process Click HERE for graphic. TRANSIMS Model Design Criteria as Derived From Federal Legislation 17 Clean Air Act Amendment The NAAQS are national, source-independent thresholds of pollutant concentrations in the atmosphere. The emissions budget is an allocation of maximum allowable pollutant quantity to the various emissions sources in a nonattainment or maintenance area so that overall pollution levels remain within, or are reduced over time, to EPA standards (NAAQS). Because each nonattainment or maintenance area has different natural and man-made environmental dynamics and social goals, the emissions budget provides for a regionally specialized formula for achieving national air quality standards. One of the primary purposes of the SIP is to develop a rationale for this regional formula. 5.4 Conformity Criteria A Conformity Determination is required for all metropolitan plans and TIPS. For some federally-funded improvements, project-level conformity tests are also required. in addition, regionally- significant non-federal projects must come from a conforming plan and a conforming TIP or be included in the conformity analyses before they proceed. TCMs are not exempt from the conformity requirements. Further, conforming projects that have a significant change in design concept and scope from that in the conformity analyses, must be recycled through the conformity process. Conformity determinations will be updated no less frequently than every three years as well as within 18 months of EPA approval of a new SIP that modifies previous emissions budgets or TCMs. The MPO and U.S. DOT (FHWA and FTA) will make the conformity determination for metropolitan plans and TIPs, the State DOT and U.S. DOT are responsible for conformity determination in rural nonattainment areas, and project sponsors and U.S. DOT are responsible for project-level determinations. All are done in consultation with EPA and state and local air quality agencies according to procedures established in the transportation conformity rule and the State's conformity SIP revision. However, all Conformity Determinations will be based on EPA/DOT prescribed criteria summarized as follows: - based on latest planning assumptions and forecasts; - based on latest EPA-approved emissions models; - based on consultation with air quality agencies; - provides for timely implementation of TCMs; - demonstrates consistency with emissions budgets in the SIP; - based on regional emissions analysis in nonattainment and maintenance areas; - in CO nonattainment areas, eliminates or reduces severity of localized CO violations (hot spots); - doesn't create hot spots; - in ozone and CO nonattainment areas, contributes to reductions of ozone and CO emissions; and, - in PM10 and NO2 nonattainment areas, contribute to reductions or not increase PM10 or NO2 respectively. 18 TRANSIMS Model Design Criteria as Derived From Federal Legislation Analysis Requirements 6.0 Analysis Requirements 6.1 Transportation Management Analysis Requirements 6.1.1 Major Investment Studies Responding to a previous tendency to fail to fully consider a wide range of intermodal options when responding to perceived transportation system requirements, planning regulations include provisions that address the management of major transportation investment studies. These provisions are intended to insure a broadly coordinated effort that provides a wide range of feasible alternatives for consideration. A major metropolitan transportation investment is generally defined as a problem that would require a solution equivalent to a controlled access arterial of more than a mile or transit projects of a similar scale. Either within, or in association with, major investment studies, transportation planners also will be required to conduct environmental analyses for input to environmental impact statements as well as emissions analyses to support conformity determinations for both metropolitan and rural nonattainment areas. Specific EPA/FHWA/FTA requirements associated with air quality studies are addressed injection 6.2 below. Finally, major investment studies will, when appropriate. serve as the supporting analysis of demand reduction and operational management strategies required for Congestion Management Systems. 6.1.2 Methodology Major investment studies should evaluate the effectiveness and cost- effectiveness of alternative transportation investments or strategies in satisfying local, state and federal goals and objectives. The analysis should consider the direct and indirect costs and reasonable alternatives with respect to: personal mobility improvement; social, economic, and environmental effects; safety; operating efficiency; land use and economic development; financing and energy consumption. 6.2 Air Quality Analysis Requirements 6.2.1 Air Quality Studies CAAA requires that conformity determinations be made on all TIPs and FHWA and FTA funded or approved projects in both metropolitan and rural nonattainment and maintenance areas. Any such transportation project not included in a conforming program or plan must be part of a regional analysis that includes all projects in the plan and TIP and the project itself. In nonattainment and maintenance areas, this determination must be based on an emissions analysis. EPA defines regionally significant to mean a facility with a principal arterial or higher functional classification as well as any facility that serves inter-regional travel needs, serves major activity centers in the region, or supports major transportation terminals in the region. In areas that are nonattainment or maintenance areas for PM10 and CO, Hot Spot analyses are required for sites (intersections) that are current or potential sources of local- TRANSIMS Model Design Criteria as Derived From Federal Legislation 19 Analysis Requirements ized pollution -- typically, congestion-based. Hot Spot analysis is not required for temporary, construction-related increases in emissions. 6.2.2 Analytical Approach Emissions analyses will be based on comparison of transportation- related emissions levels, in each of a series of "snapshot" analysis years between a Baseline and Action Scenario and/or to the emissions budgets allocated for the transportation system component (traffic, transit, etc.). In each analysis year, a Baseline Scenario will be analyzed. This scenario, or alternative, will consist of: - all existing, regionally significant highway/transit facilities, services, and activities; - all on-going travel demand management or transportation system management activities; and, - all regionally significant projects under construction or undergoing right-of-way acquisition from the first 3 years of the previously conforming plan and/or TIP or those that have completed the NEPA process. One or more Action Scenarios also will be analyzed. Action Scenarios will consist of: - all facilities, services and activities in the Baseline Scenario; - all approved TCMs and regionally significant projects in the transportation plan that will be operational or in effect in the analysis year; - all travel demand management programs and transportation system management activities known to the MPO that also have been adopted, modified, or funded; and - all other expected, regionally significant projects, activities, or services. Emissions and concentration for each of the relevant pollutants and scenarios (by analysis year) will be predicted. This prediction will be based on forecasted changes in population, land use, and commercial activity for the year under analysis. This forecast also will include projections of background emissions for each pollutant from sources other than those explicitly modeled. The ambient temperature assumed in the analysis shall be consistent with those used to compute the emissions budgets in the SIP. Criteria for success is met if. one, the predicted regional emissions for the Action Scenario(s) are less than those predicted for the Baseline Scenario; two, they can be expected to remain so for any intervening period between milestone years; and three, they remain less than those levels allocated in the SIP. 6.2.3 Models Federal rule-making has established that the latest approved version of the MOBIL motor vehicle emissions model is the required emissions model for emissions analysis, hot spot analysis, and conformity determinations outside of the state of California. Within California, EMFAC is the approved motor vehicle emissions model for air quality analyses conducted under the CAAA. However, transportation planners remain unsatisfied with the predictive capabilities of these models. Addressing these limitations, is believed to be a functional requirement that will be discussed in Section 6. While federal regulations do not prescribe a specific transportation model, they do prescribe features that are required for CO and ozone areas as classified as serious and above. These required features include: 20 TRANSIMS Model Design Criteria as Derived From Federal Legislation Analysis Requirements - a network-based transportation model that relates travel demand and system performance to best available data for land use patterns, population demographics, employment transportation infrastructure and transportation policies; - sensitivity to ambient temperature; - representations that are in accordance with acceptable professional practice, and reasonable for purposes of emission estimation; - validation within the last 10 years against vehicle ground counts; - capacity-sensitive traffic assignment methodology; - link assignment times must be in agreement with zone-to-zone travel times; - free-flow speeds on network links must be based on empirical observations; - traffic speeds and delays must also be sensitive to traffic volume; - peak and off-peak travel requirements and travel times must be provided; - trip generation, trip distribution and mode choice must be sensitive to pricing; - documented correspondence between the assumed land-use scenario and the future transportation system being represented; - a trip-generation dependency on the accessibility of destinations via the transportation network is strongly encouraged; - a dependency between regional economic and population growth on the accessibility of destinations is also strongly encouraged. In addition, Highway Performance Monitoring System (HPMS) estimates of vehicle miles traveled (VMT) shall be considered the standard for this principal MOP except where and when EPA and FHWA determine that HPMS is inappropriate. When model estimates are different from the HPMS data, appropriate methods will be applied to calibrate the model results to the HPMS estimates for the same period. 6.2.4 Measures of Performance (Sensitivities) - Vehicle Miles Traveled (VMT) - Speed - Acceleration - Vehicle and Engine Characteristics - Fuel - Startup (Hot vs. Cold Start) - Idling - the effect of trip frequency on evaporative emissions TRANSIMS Model Design Criteria as Derived From Federal Legislation 21 Derived Functional Requirements for TRANSIMS 7.0 Derived Functional Requirements for TRANSIMS 7.1 Overview The purpose of TRANSIMS is to provide an analytical environment within which state and local transportation planners can meet the programmatic requirements that have been previously discussed. To meet this requirement, this environment must be adaptable to the unique requirements of each local planner. This is accomplished by maintaining a core of fundamental functional representations that can be readily and easily applied to data characterizing the local environment, as well as proposed and forecasted changes, to form a complete representation of the objective region. However, to meet the evolving requirements for more quantitative and accurate analysis, TRANSIMS also must incorporate a greater level of detail than is found in current regional planning models that are applied to land use and regional economic development. To achieve these objectives, TRANSIMS must represent: - the land use and demographic characteristics of different regional transportation domains; - the natural environment associated with that domain to include topography, meteorology, and background levels of pollution; - an intermodal transportation network down-to and including minor arterials, along with all potential nodes; - representative populations and commercial environments based upon survey data for households, commercial and industrial entities; - the unique travel decisions (time-of-day, origin/destination, route, mode, etc.) of individuals based on a wide range of socioeconomic characteristics; - automobile and commercial transportation systems in sufficient detail to incorporate the air quality emission effects of different engine and fuel characteristics; - the detailed (micro) and dynamic aspects of traffic in a region of interest including congestion, signals, incident detection, and driver behavior; - the unique influences of traffic on congestion and air quality; and - provide user-friendly analytical support capabilities. In addition to these requirements, an entity-level simulation will be required for three reasons: - first, traffic studies will continue to require representations of detailed characteristics of travelers, vehicles and the transportation system components themselves; - second, model validation will require comparison of simulation output to traffic counts and other survey data that is collected at the entity level; and, - third, for theoretical reasons related to the ability of inaccurate aggregated models to generate false support for themselves, entity-level representations will insure that system-level behavior is. derived explicitly from valid entity- level representations. Figure 6 presents a diagram of the TRANSIMS, high-level, functional requirements in terms of the policy environment portrayed in Figure 1. 22 TRANSIMS Model Design Criteria as Derived From Federal Legislation Derived Functional Requirements for TRANSIMS FIGURE 6. TRANSIMS Modeling and Analysis Environment Click HERE for graphic. TRANSIMS Model Design Criteria as Derived From Federal Legislation 23 Derived Functional Requirements for TRANSIMS 7.2 Component Requirements The analytical environment consists of- a complex representation of the transportation domain that characterizes a region; a domain- independent transportation simulation/ model; and, a set of supporting programs and facilities to translate simulation histories into statistics that can be used to make decisions with respect to public transportation and air quality goals and objectives. Key representational requirements are: - entity-level representation of individual travelers and freight items; - data bases and simulations that support the representation of relatively sophisticated behavior as well as choice/utility models that are sensitive to travel time constraints, preferences, travel behavior, cost, and perceived quality of service; - travel and environmental models, system simulations, and component models that are sensitive to relatively detailed representations of environmental and vehicle characteristics correlated to both the geographic and demographic distribution of travelers; and - simulation of continuous traffic, transit, freight, bike, and pedestrian travel over the course of extended period (incorporate both peak and non-peak travel requirements) different days of the week, months, and seasons etc. 7.2.1 Transportation System Data Component (Statistical Models, Data Structures, and Data Bases that Characterize a Transportation Region) Travel behavior is strongly influenced by the unique transportation requirements associated with different populations as well as their spatial and temporal relationships to commercial, government, entertainment and other public and private facilities. To simulate realistic transportation demand, TRANSIMS will require both statistical models and data to represent these populations, activities, and environments. The analytical environment must also accurately represent both current and future transportation infra- structure, facilities, services and operational characteristics. Finally, the simulation environment must represent those aspects of the natural environment that influence air quality. These representational requirements necessitate four basic data sources and information as indicated in Figure 6. Land Use. Patterns of land use as well as the demographics of the population generate transportation requirements and patterns of vehicle use that affect, for example, air quality. TRANSIMS will require representations of geographic clusters in terms of their population, residential, commercial activities and terrain referenced to geographic coordinates. These representations will provide the basis for spatially referencing populations, residential, and commercial activities. They will also provide the basis for linking traveler characteristics, origins, and destinations in trips and trip chains as well as for characterizing the ground as it relates to vehicle performance and emissions. Moreover, they provide the structural basis for forecasting. To represent the evolution of the region in time, TRANSIMS must employ techniques to modify land use and demographic representations based on input from external sources. Because of the poorly understood cause and effect relationships between infrastructure policy and subsequent patterns of growth, the TRANSIMS analytical methodology should naturally support forecasting methods. Although the TRANSIMS project is not specifically funded to satisfy this requirement, its relationship to this problem is obvious. 24 TRANSIMS Model Design Criteria as Derived From Federal Legislation Derived Functional Requirements for TRANSIMS, General representational requirements identified in our policy research include - the land use and demographic characteristics of different regional transportation domains are required, along with - the environment associated with those domains to include topography (including urban terrain), meteorology, and background levels of pollution from static. nonmobile sources, and a - methodology that explicitly relates any future transportation system being represented to the associated land-use scenario. Traveling Population. The purpose of the representative populations is to produce realistic travel requirements for the intermodal system and also to generate appropriate distributions for the behavioral models of travelers. To support this requirement, the TRANSIMS project must provide suitable population, residential and commercial data bases. It must also provide the methodologies and environment Co ascertain the variables that most effectively discriminate travel demand and behavior for given problems. Driving, as well as biking and walking, behavior is sensitive to the demographic characteristics of drivers and has a significant effect on fuel consumption, emissions, accidents, and incidents of congestion. For this reason, TRANSIMS must incorporate the demographic characteristics of each individual driver as well as methods for mapping these characteristics to the dynamic aspects of driver behavior and their affects on driver-system, driver-driver, and driver-vehicle interactions. Vehicle characteristics also influence fuel consumption and emissions. For TRANSIMS to faithfully represent the air quality impacts of different populations and transportation systems, it must incorporate representations of vehicles that are sensitive to the relationships between driver behavior, engine characteristics, fuel type, vehicle performance, and emissions. TRANSIMS must be capable of generating representative disaggregate populations from aggregate statistical data about the social, economic and demographic characteristics of the region. Extending available census and, survey data to disaggregate populations that accurately discriminate the unique transportation requirements of different demographic population profiles is a research requirement for TRANSIMS. General representational requirements identified in our policy research include: - aggregated populations and commercial demographics as well as commercial activity profiles (hours of operation etc.) to support the generation of - disaggregated traveler populations to drive the transportation simulation; as well as - automobile and commercial transportation systems in sufficient detail to incorporate the air quality emission effects of different engine and fuel characteristics. Atmosphere. Meteorological conditions exert a significant influence on air quality. These conditions include seasonal temperatures and humidity, background air quality from non-mobile sources, prevailing winds, and the influence of large natural features such as mountains and oceans on air movement patterns. Although these phenomena are relatively well understood, developing an appropriately scaled, regional air quality model that can efficiently and accurately translate explicit representation of individual TRANSIMS Model Design Criteria as Derived From Federal Legislation 25 Derived Functional Requirements for TRANSIMS vehicle emissions into a dynamic representation of air quality for a region or major air basin may present a significant computational challenge for TRANSIMS. Determining the levels of fidelity and aggregation that satisfy these criteria remains an unresolved analytical requirement for TRANSIMS. General representational requirements identified in our policy research include the natural environment associated with a transportation region to include topography, meteorology, and background levels of pollution. Intermodal Transportation System. The transportation system includes a set of mode-specific links and nodes that characterize the transportation constraints on vehicles and travelers. To support transportation system design and air quality studies effectively, TRANSIMS must represent the influence of all current and anticipated transportation facilities, technologies and operational procedures on traveler and vehicle behavior at both the micro-(individual) and macro (system) level. Specifically, the network must include all interstate, freeway, expressway, as well as other principal and minor arterials and possibly major collectors. It must also include any unique transit links as well as unique links for pedestrian and bicycle traffic. While near-term TRANSIMS design will not include an explicit representation of air, rail and waterborne transport, the network must include the intermodal transfer of travelers and freight to-and-from surface facilities to these carriers. To minimize the computational burden associated with simulating travel, development of efficient data structures for roadways and pathways will be an important design issue for TRANSIMS. Traffic nodes represent the intersection of more than one link, mode of travel, or fink class such as would occur in transitioning from a public access highway to a toll road. Traffic nodes typically incorporate some method of vehicle control (signals) as well as route selection (function of congestion and pricing) and, occasionally, mode transfer. Transportation nodes influence overall traffic flow as well as the air quality implications from congestion. Because of anticipated reductions in the rate of growth of new roadways, many of the new transportation system improvements are expected to focus on improved design and management of transportation nodes to maximize overall system capacity by efficiently distributing peak demand across the system. The increasing sophistication of automated traffic control technologies and the uncertainties associated with driver behavior (choice and utility), effective representation of modern traffic nodes will present a challenge to TRANSIMS design. Intermodal nodes are important features of a number of demand reduction proposals and TCMs. Important features of these nodes include parking and freight transfer facilities, as well as mode transfer characteristics that affect travel -time, cost and traveler preferences for both passengers and freight. General representational requirements identified in our policy research include an intermodal transportation network down-to and including minor arterials and pathways, along with detailed characterization of all potential nodes. Specific representational requirements identified in our policy research include representation of: 26 TRANSIMS Model Design Criteria as Derived From Federal Legislation Derived Functional Requirements for TRANSIMS - general system characteristics to include lane miles, intersection and roadway width and lanes, roadway grade, parking, freight, and mode transfer facilities, HOV lane miles, node characteristics, roadway functional class, and type and location of construction; - operational characteristics such as channelization, traffic surveillance and control systems, motorist information systems, ramp metering, traffic control centers, and standard as well as computerized signal systems; - measures to encourage high occupancy vehicle (HOV) use such as HOV lanes, - HOV ramp bypass lanes, guaranteed ride home programs, and employer trip reduction ordinances; - public transit capital improvements such as exclusive rights-of- way (rail and bus), bus bypass ramps, park and ride as well as mode change facilities, and paratransit facilities; - public transit operational improvements such as service enhancement or expansion, signal preemption and transit information systems; - explicit travel cost data to include tolls and congestion pricing management systems; - intelligent vehicle highway system (IVHS) and advanced public transportation system technology. 7.2.2 Transportation Simulation Component The transportation simulation consists of four activities: - generate realistic transportation requirements for the system as a whole while providing feedback; - exercise the transportation system; - apply vehicle travel histories to produce selected emissions and their resulting influence on the atmosphere; and, - provide appropriate travel histories in statistical form for analysis by transportation and air quality planners. Household and Commercial Activity Disaggregation Component. From an understanding of the size and demographic features of the regional population (aggregated population discussed above) and spatial and characteristic distribution of commercial and other activities (Land Use data discussed above), the disaggregation component produces a complete set of travel requirements for each population cluster. Specifically, the component should generate, for each household in each population cluster, a set of required travel activities characterized by travelers, origin, destination, time constraint, and purpose. The component should further clusters these activities into trip chains according to spatial and temporal constraints. Travel requirements are, therefore, represented as a set of trip chains characterized by a set of origin destination pairs with associated time constraints, as well as a driver and passengers. By inheritance, these trips can be further characterized by the driver's demographic characteristics, vehicle type and driver pattern of behavior and preferences. The Disaggregation Component should produce a travel requirements data base that accurately reflects the number and distribution of travel requirements that the true regional population would produce during the period being simulated. Although no TRANSIMS Model Design Criteria as Derived From Federal Legislation 27 Derived Functional Requirements for TRANSIMS individual trip need be linked to a predictable event by the true population, the resulting distribution of trips should reflect, in space and time, representative regional transportation requirements. Because of the limitations of existing data and statistical techniques, development of a Disaggregation Component is a significant research requirement for TRANSIMS. General representational requirements identified in our policy research include: - a trip-generation dependency on the accessibility of destinations via the transportation network; - a network-based transportation component that relates travel requirements and system performance to best available data for land use patterns, population demographics, employment, transportation infrastructure and transportation policies; - treatment of the unique travel decisions (time-of-day, origin/destination, route, mode, etc.) of individuals based on the wide range of socio-economic characteristics that influence personal travel decisions; and - treatment of adopted congestion management alternatives including alternate work schedules. Trip/Travel Planner. The Travel/Intermodal Route Planner should convert the trip requirements from the Disaggregation Component into intermodal travel plans based on the space and time constraints of the trip, demographically-defined traveler preferences, and transportation system characteristics. Through one or more optimization techniques, this component should select model-routes choices that optimize the travelers transportation utility function subject to the constraints imposed by the trip and transportation system constraints. Because of the interrelationship between travel requirements and planning, previous modeling experience has indicated that equilibrium methods are required to ensure that realistically efficient travel requirements are generated. In Figure 6, these methods are represented, for between-model equilibration, as a feedback loop. Because of the complexity associated with this optimization task, as well as the unique ability of humans to do this effectively, realistic mode/route assignment for large, complex populations is a research requirement for TRANSIMS. General representational requirements identified in our policy re- search include: - trip distribution and mode choice must be sensitive to pricing; - traffic assignment methodology must be sensitive to capacity; and - link assignment times must be in agreement with zone-to-zone travel times; Specific representational requirements identified in our policy research include representation of: - congestion management alternatives including: ridesharing (car and van pools); walking or biking; parking management; freight movement options; telecommuting; and public transportation. - trip travel time and cost; 28 TRANSIMS Model Design Criteria as Derived From Federal Legislation Derived Functional Requirements for TRANSIMS - volume of cargo and passengers moved (usage); - available facilities (potential origins and destination choices); - subsystem and system capacity; - accidents / safety; - ease of access; - mode transfer time, cost, and ease; and, - perceived quality of service. Travel Network Simulation. The centerpiece of the TRANSIMS environment is the simulation that results from applying, to the regional transportation data base, the transportation plans produced by the Planner as well as the Land Use (ground surface charac- teristics), Population (driver behavior), and Intermodal Transportation System data. However, a unique challenge for TRANSIMS results from ISTEA and CAAAs implicit requirement to integrate, into a single simulation, the analytical requirements that were previously satisfied by two classes of models -- detailed traffic and air quality simulations and more aggregated regional planning and forecasting models. Therefore, the TRANSIMS traffic simulation is required to satisfy the detailed representational requirements of previous traffic simulations within an environment that includes a large metropolitan area over an extended time period. The computations that can be expected to result from this integration generate a research requirement to investigate new and more efficient simulation methods. The required functionality of the simulation includes the ability to represent and record, at both the entity (vehicle/driver) and system level, the results of the interactions occur between the driver and other drivers (passing and accidents), the driver and the transportation system (signals and congestion), and the driver's vehicle and the environment (engine performance and emissions). The magnitude of the simulated environment along with some of the unique features of congestion generate a number of research, design, and analysis issues related to determining the minimal representational levels necessary to provide accurate characterizations of these interactions. The term minimal representational levels applies to both input data sets and resulting simulation output (histories). General representational requirements identified in our policy research include: - free-flow speeds on network links must be based on empirical observations; - traffic speeds and delays must also be sensitive to traffic volume; and - peak and off-peak travel requirements and travel times must be incorporated. Specific representational requirements identified in our policy research include representation of: - congestion management alternatives including traffic operations, pedestrian and bicycle facilities, parking management, freight movement options, congestion pricing, and incident management; - operational alternatives including multiple general purpose lanes as well as intersection and roadway width, channelization and access management, traffic surveillance TRANSIMS Model Design Criteria as Derived From Federal Legislation 29 Derived Functional Requirements for TRANSIMS and control systems, motorist information systems, ramp metering, traffic control centers, and computerized signal systems; - measures to encourage high occupancy vehicle (HOV) use such as HOV lanes, HOV ramp bypass lanes, guaranteed ride home programs, and employer trip reduction ordinances; - public transit capital improvements such as exclusive rights-of- way (rail and bus) bus bypass ramps, park and ride as well as mode change facilities, and paratransit facilities; - public transit operational improvements such as service enhancement or expansion, signal preemption, fare reductions, and transit information systems; and - intelligent vehicle highway system (IVHS) characteristics and technologies. Proposed Measures of Effectiveness(MOE) include: - level of service (LOS); - vehicle miles of travel (VMT) and average daily traffic by vehicle class; - number of vehicles and persons using HOV (and other) lanes; - proportion of travel, persons and vehicles congested or de - proportion of travel time under congestion or delay; - nature and location of congestion and incidents; - delay per: lane mile, VMT, trip, vehicle, person, incident, and construction; - average travel time per trip; - persons/hour on facility or corridor; and - persons per vehicle. Air Quality Simulation. Selected results of the travel simulation, along with local meteorological characteristics (Atmosphere) and surface characteristics (Land Use), should be applied to a separate air quality simulation that determines vehicle emissions by pollution type. The resulting surface chemistry data must be accumulated, along with background emissions from non-mobile sources, in space and time. As a function of regional meteorological conditions, these accumulated surface emissions must then be applied to air chemistry and dispersion models to determine where, to what extent, and for how long selected levels of pollution accumulate in the atmosphere. Although the physical processes associated with each of these supporting submodels is reasonably well understood, determining appropriate sampling intervals and levels of aggregation present analysis and design requirements to the TRANSIMS. General representational requirements identified in our policy research include: - sensitivity to ambient temperature; - representation of construction-related fugitive PM-10; - representations that are in accordance with acceptable professional practice, and reasonable for purposes of emission estimation; and - validation within the last 10 years against vehicle ground counts. 30 TRANSIMS Model Design Criteria as Derived From Federal Legislation Derived Functional Requirements for TRANSIMS Specific representational requirements identified in our policy research include representation of: - vehicle speed and acceleration; - vehicle, fuel, and engine characteristics; and - startup (Hot vs. Cold Start) and idling. Analysis Support Environment. Transportation and air quality planners who use TRANSIMS will require, along with raw output data, hardware and software that will allow them to effectively interpret and analyze that data. TRANSIMS, therefore, has a requirement to develop a set of computer-based tools that support experimental design, sensitivity and statistical analysis, and visual representation in multiple media. These tools will support all of the functional components of the TRANSIMS environment: - Data Base development and review: Land Use, Transportation Population, Transportation System, and Atmosphere; - output Data review and manipulation: Disaggregation Simulation Travel Planner Transportation Simulation. and Air Quality; and - model review. TRANSIMS Model Design Criteria as Derived From Federal Legislation 31 Definitions, Acronyms, and Abbreviations 8.0 Definitions, Acronyms, and Abbreviations The definitions of all terms, acronyms and abbreviations are presented in this section. CAAA Clean Air Act Amendments of 1990 CMS Congestion Management System CO Carbon Monoxide DOT US Department of Transportation EIS Environmental Impact Statement EPA Environmental Protection Agency FHWA Federal Highway Administration FTA Federal Transit Administration HOV High Occupancy Vehicle IMS Intermodal Facilities and Systems Management System ISTEA Intermodal Surface Transportation Efficiency Act of 1991 ITS Intelligent Transportation System MPO Metropolitan Planning Organization NAAQS National Ambient Air Quality Standards NHS National Highway System PM-10 Particulate Matter less than 10 microns in diameter PMS Pavement Management System PTMS Public Transportation Facilities and Equipment Management System SIP State Implementation Plan SMS Highway Safety Management System STIP State Transportation Improvement Program TCM Transportation Control Measure TIP Transportation Improvement Program TMA Transportation Management Area TMS Traffic Monitoring System TSM Transportation System Management VOC Volatile Organic Compounds VMT Vehicle Miles of Travel 32 TRANSIMS Model Design Criteria as Derived From Federal Legislation References 9.0 References Ducca, F. (1994) "Future Directions in Travel Forecasting" Department of Transportation, Federal Highway Administration. Federal Register (1993) Part HI: Environmental Protection Agency. 40 CFR, Part 5 1: Criteria and Procedures for Determining Conformity to Transportation Plans; Proposed Rule. Federal Register (1993) Part III: Department of Transportation, Federal Highway Administration, and Federal Transit Administration. 23 CFR Part 450 (FHWA) and 49 CFR Part 613 (FTA) Statewide Transportation Planning and Metropolitan Planning; Proposed Rule. Federal Register (1993) Part IV: Department of Transportation, Federal Highway Administration, and Federal Transit Administration. 23 CFR Part 500 et. al. (FHWA) and 49 CFR Part 614 (FTA) Management and Monitoring Systems; Proposed Rule. Federal Register (1993) Part III: Department of Transportation, Federal Highway Administration, and Federal Transit Administration. 23 CFR Part 450 (FHWA) and 49 CFR Part 613 (FTA) Statewide Transportation Planning and Metropolitan Planning; Proposed Rule. Federal Register (1993) Part II: Department of Transportation, Federal Highway Administration. and Federal Transit Administration. 23 CFR Part 450 (FHWA) and 49 CFR Part 613 (FTA) Statewide Transportation Planning and Metropolitan Planning; Rule. Federal Register (1993) Part II: Department of Transportation, Federal Highway Administration, and Federal Transit Administration. 23 CFR Part 500 et. al. (FHWA) and 49 CFR Part 614 (FTA) Management and Monitoring Systems; Interim Final Rule. Federal Register (1993) Part II: Environmental Protection Agency. 40 CFR, Part 51: Air Quality: Transportation Plans, Programs, and Projects; Rule. 93 CFR Federal or State Implementation Plan Conformity; Rule. Harvey, G and E. Deakin (1992) "A Manual for Transportation Air Quality Modeling for Metropolitan Planning Organizations" November 30, 1993 Revised Draft prepared for the National Association of Regional Councils. Karash, K., C. Schweiger, and L. Harman (1994) "Identification of Transportation Planning and Data Collection Requirements in Federal Legislation" prepared for the Volpe National Transportation System Center. TRANSIMS Model Design Criteria as Derived From Federal Legislation 33
