Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
Free market forces respond to the future vision. We need to better integrate networks and demographics. From a strategic viewpoint, we need to do a better job of establishing priorities. We cannot model everything. In some cases, a broader information system may be enough to answer a question without detailed modeling. We also need to conduct reasonability checks related to estimation, calibration, validation, prediction, and sensitivity. I will highlight a few policy issues and model applica- tion needs. Land use patterns are changing to include mixed use and infill development, transit- oriented devel- opment, and bicycle- and pedestrian- friendly environ- ments. Publicâprivate partnerships are also more important today. These partnerships relate to both subsi- dies to encourage private development and privatization of toll roads. We also need to be aware of the influence of changing technology, including intelligent transporta- tion systems (ITS) to maximize flow and provide infor- mation to drivers, telecommuting, and changing work environments and dynamic pricing. We are also seeing more interest in financial constraint issues, emergency preparedness initiatives, and congestion or time- of- day pricing. There is interest in time- of- day pricing for a number of reasons. For example, the North Central Texas Coun- cil of Governments has been asked to assess the impact of increasing peak- period tolls on carpooling, vanpool- ing, and transit use. We also need to know what the impact is on moving discretionary trips to off- peak peri- ods, moving short trips to the frontage roads, and encouraging trip chaining. Other possible impacts relate to increasing flextime hours, work schedule changes, and telecommuting. Finally, we need to be able to assess whether increasing peak- period tolls will reduce trip length over time and increase reliability on the system. We need to provide policy makers with a list of the potential impacts and the possible magnitude of these impacts. As modelers we do not always do a good job of inter- preting the model results. We do not spend enough time developing and using performance measures that focus on trip performance rather than link performance. We also need other measures that better address issues of interest to policy makers and the public. Performance measures that focus on multimodal user benefits, envi- ronmental justice, accessibility by mode, and trip- time reliability are needed. Other measures that address crashes, injuries, and fatalities by mode, as well as fuel consumption would also be of benefit. In conclusion, it is important that we continue to maintain an objective technical process. We need to tran- sition from existing models to better models. We need to do a better job of training and documenting these new models. It is also important to keep the new models user friendly. Universities need to educate more modelers and MPOs need to ensure competitive salaries for modelers. Finally, it is important to maintain a focus on who is the client of the modeling process. Modeling is not an end in and of itself. Our job as modelers is to present the model results to policy makers and the public. FEDERAL DEMANDS ON TRAVEL DEMAND MODELS Edward Weiner My presentation focuses on the various federal require- ments that influence the use of travel demand models, including provisions of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA- LU). SAFETEA- LU continues the same basic transportation planning requirements for MPOs and states. The three basic planning documents that must be developed include a long- range transportation plan, the transportation improvement program (TIP), and the financial plan. The long- range plan and the TIP have to be updated every 4 years. Numerous options may be considered in these plans to address transportation issues in an area. Examples of these options include transportation and land use coor- dination and new and expanded transportation facilities. Transportation system management components, trans- portation demand management strategies, ITS, and non- motorized travel may also be considered. There are no specific travel demand modeling require- ments associated with the development of these plans. However, there are a number of transportation planning factors that should be considered. These factors include supporting economic vitality and increasing safety and security. Other factors address increasing accessibility, enhancing mobility options, protecting the environment, and promoting energy conservation. The consistency between transportation and development patterns should also be examined. Additional factors to consider include enhancing integration and connectivity of the system, promoting efficient system management and operation, and preserving the existing transportation system. There are two basic environmental requirements related to the transportation planning process and the project development process. The first requirement relates to the National Environmental Policy Act (NEPA) and the second addresses transportation air quality con- formity analysis. NEPA requires an estimate of environ- mental impacts and an evaluation of land development effects of new highways. Mitigation strategies must be developed and implemented if there are any negative impacts. An air quality conformity analysis that meets 6 INNOVATIONS IN TRAVEL DEMAND MODELING, VOLUME 1
