David L Kurth

ASSESSMENT OF QUICK-REFUSAL AND NO-CONTACT NONRESPONSE IN HOUSEHOLD TRAVEL SURVEYS

Summarized are the procedures and results of a survey used to obtain information on persons in households who quickly refused or could not be contacted to respond to the 1997 Denver Region Travel Behavior Inventory household travel survey. Quick-refusals are people who hang up the telephone without listening to the full short introduction and the first question of the recruiting call. In this study, 1,000 households that quickly refused or could not be contacted in the household survey were sent a letter and a short survey on household demographics in an effort to obtain limited data about the household. To test the impact of a small incentive on the follow-up survey, half the samples were given a

IMPLEMENTATION OF "HIGHWAY CAPACITY MANUAL"-BASED VOLUME-DELAY FUNCTIONS IN REGIONAL TRAFFIC ASSIGNMENT PROCESS

2 cash incentive, and the other half received no incentive. The survey included questions asking why the households did not respond to the survey as well as some limited demographic and travel questions. The results of the survey showed some differences between the nonresponding households and the households that did respond to the household survey. At the same time, the survey results suggested that trip rates for the two groups might be very similar. The results suggest that the hypothesis that quick-refusal and no-contact households travel more than households responding to travel surveys may not be valid.

Market-Based Framework for Forecasting Parking Cost in Traditional and Microsimulation Modeling Applications

Recent model development efforts for the travel demand forecasting process have focused on increasing the consistency and reasonableness of the results. A major target of these efforts has been the traffic assignment process and, more specifically, improving the estimates of congested travel speeds resulting from traffic assignments. A number of studies and enhancements have centered on the volume-delay functions used for the assignment process. Many of these studies have used the workhorse volume-delay function, the BPR function, and have investigated modifications to the function coefficients. In its recent update of the Albuquerque Area Travel Models, the Middle Rio Grande Council of Governments successfully implemented a regional traffic assignment process based on capacity estimation techniques and volume-delay functions documented in the Highway Capacity Manual. The assignment procedures developed for the Albuquerque area resulted in volume-delay functions that produced accurate traffic volumes whil...

Transit Path Building: To Multipath or Not to Multipath

Parking cost is an important variable in determining mode choice, yet it receives little attention in most travel forecasting models. This paper presents a framework for modeling parking supply and cost that has three advantages over most parking cost models: a market-based approach is used to equilibrate parking demand with parking supply; actual parking costs paid by groups of travelers rather than average parking costs are estimated for each transportation analysis zone; and estimates are made from longitudinal data. This framework has been applied successfully in a traditional four-step travel model and is being used in practice. It also provides additional opportunities for application in a segmented manner or in concert with a microsimulation modeling approach. Mode choice results based on aggregate and segmented applications of the framework are substantially different. Improved forecasting of parking costs should be an important consideration in any new model development. In recent years, substantial efforts have been focused on household interactions and activity modeling. Although the understanding of travel behavior has improved substantially, the improved techniques still depend on good input data for credible forecasts.

SMALL-AREA TRIP-DISTRIBUTION MODEL

Two basic options exist for modeling transit path choice in the travel forecasting process: (a) a detailed mode choice model and (b) deterministic procedures underlying transit multipath, path-building algorithms. These two options require different approaches to transit path building, mode choice, and transit assignment. Modeling decisions regarding transit path-building techniques and the amount of transit path choice incorporated into mode choice models directly affect the ability of travel models to consistently model mode choice and transit use. Options and their implications are presented for transit path building and mode choice. An analysis is presented of the success of alternate transit path-building techniques in reproducing known transit paths as reported by transit users in Denver, Colorado; analysis of several commonly used transit path-building validation techniques is also given. Suggestions are made for interface transit path choice and transit path building on the basis of the results of the empirical transit path-building tests. Two primary suggestions applicable to current planning processes are made. First, transit path choice should be performed in only one component of the forecasting process, such as transit path building or mode choice, to minimize inconsistencies in the modeling process. Second, disaggregate measures such as prediction success tables comparing modeled boardings to reported boardings for individual observations of transit trips should be compiled for validation of transit networks and transit path-building procedures.