关键词: 交通运输经济, 效益测算, Logsum差异, 嵌套Logit模型, 出行者, 情景分析

Abstract:

Transport policy, project investment and management measures usually impact on travelers’ behavior, and then play a role on the economic benefits in transportation system. It is necessary to scientifically evaluate the influences and estimate the user benefits. From the analysis of the commonly used methods to estimate user benefits in transportation economics, this paper focuses on the methodology based on Logsum difference and consumer surplus. It builds a nested Logit model structure of travel decisionmaking from destination choice, mode choice and route choice through upper level to lower, and gives the mathematical descriptions and expressions of traveler utility and probability, and then proposes the formulas to estimate traveler benefits based on a nested Logit model and Logsum difference; it also establishes a base scenario and 5 alternative scenarios in an example and calculates the traveler benefits(or losts) across scenarios using Logsum method, and compares its results to rule- of- half method. Results show that the monetized differences in Logsums gives a more exact result for traveler benefits than rule-of-half when there is a big change on the variables compared to base scenario.

Key words: transportation economy, user benefit estimation, Logsum difference, nested Logit model, traveler, scenario analysis