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Title:

VERIFYING ACCURACY OF REGIONAL MODELS USED IN TRANSPORTATION AND AIR QUALITY PLANNING: CASE STUDY IN SACRAMENTO, CALIFORNIA, REGION

Accession Number:

00985922

Record Type:

Component

Availability:

Transportation Research Board Business Office

500 Fifth Street, NW
Washington, DC 20001 United States
Order URL: http://www.trb.org/Main/Public/Blurbs/155518.aspx

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Order URL: http://worldcat.org/isbn/0309094933

Abstract:

Model validation involves the comparison of model forecasts with observed data that are not used in model development to identify model prediction capabilities. In this study, the historical forecasting method of validation is applied to the original version of the Sacramento, California, regional travel demand model (estimated with 1991 data) with observed data obtained in 2000 to test the accuracy of the model over a 9-year period. Two simulations were used to test the model's accuracy and its representation of induced travel. The results indicate that the model's functional forms and parameters overestimate vehicle miles traveled, hours traveled, and hours of delay (by 5.7%, 4.2%, and 17.1%, respectively) and that the model captures about half of estimated induced travel (i.e., elasticity of 0.14 versus 0.22). It appears that if the model were used for air quality analyses in this region, its overestimation of daily vehicle travel would provide a relatively generous margin of error with respect to meeting emissions budgets. However, in environmental impact statements for new highway projects, the model's upward bias would tend to overestimate no-build travel demand and congestion and, thus, the need for the projects. Compared with the no-build alternative, the magnitude of change for the highway alternative would have to be greater than the model error to be considered significantly different.

Supplemental Notes:

This paper appears in Transportation Research Record No. 1898, Travel Demand and Land Use 2004.

Monograph Accession #:

00985916

Language:

English

Corporate Authors:

Transportation Research Board

500 Fifth Street, NW
Washington, DC 20001 United States

Authors:

Rodier, C J

Pagination:

p. 45-51

Publication Date:

2004

Serial:

Transportation Research Record

Issue Number: 1898
Publisher: Transportation Research Board
ISSN: 0361-1981

ISBN:

0309094933

Features:

References (19) ; Tables (5)

Uncontrolled Terms:

Air quality planning

Geographic Terms:

Sacramento (California)

Subject Areas:

Highways; Planning and Forecasting; I72: Traffic and Transport Planning

Files:

TRIS, TRB, ATRI

Created Date:

Feb 14 2005 12:00AM

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