An Evaluation of Assignment Algorithms and Post-Pro cessing Techniques for Travel Demand Forecast Models

Type of Document Master's Thesis
Author Goldfarb, Daniel Scott
Author's Email Address dgoldfar@vt.edu
URN etd-04052003-152157
Title An Evaluation of Assignment Algorithms and Post-Pro cessing Techniques for Travel Demand Forecast Models
Degree Master of Science
Department Civil Engineering
Advisory Committee
Advisor Name Title
John Collura Committee Chair
Antonie Hobeika Committee Member
Sam Tignor Committee Member
Keywords

* Post-Processing
* Travel Demand Forecast

Date of Defense 2003-04-01
Availability unrestricted
Abstract

An Evaluation of Assignment Algorithms and Post-Processing Techniques for Travel Demand Forecast Models

Daniel S. Goldfarb

(ABSTRACT)

The purpose of this research project was to evaluate the techniques outlined in the National Cooperative Highway Research Program Technical Report 255 Highway Traffic Data for Urbanized Area Project Planning and Design (NCHRP-255), published in 1982 by the Transportation Research Board. This evaluation was accomplished by using a regional travel demand forecast model calibrated and validated for the year 1990 and developing a highway forecast for the year 2000. The forecasted volumes along the Capital Beltway (I-495/I-95) portion located in the State of Maryland were compared to observed count data for that same year. A series of statistical measures were used to quantitatively evaluate the benefits of the techniques documented in NCHRP-255.

The primary research objectives were:

· To critically evaluate the ability of a regional travel demand forecast model to accurately forecast freeway corridor volumes by comparing link forecast volumes to the actual count data.

· To evaluate and determine the significance of post-processing techniques as outlined in NCHRP-255.

The most important lesson learned from this research is that although it was originally written in 1982, NCHRP-255 is still a very valuable resources for supplementing travel demand forecast model output. The “raw” model output is not reliable enough to be used directly for highway design, operational analysis, nor alternative or economic evaluations. The travel demand forecast model is a tool that is just part of the forecasting process. It is not a turn-key operation, and travel demand forecasts cannot be done without the application of engineering judgment.

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