关键词: 交通工程, 组合模型, 无约束优化方法, C-Logit模型, 模式选择

Abstract: A general unconstrained optimization model of combined travel-destination-mode-route choice was established based on expected utility theory. The choice of travel or not, the choice of travel destination, the choice of mode and the distribution of traffic were analyzed in a unified framework. The travel impedance of the combined model, the probability or conditional probability of users choosing travel, destination, mode and path respectively, and the characteristics of satisfaction function were derived. The equivalence, existence and uniqueness conditions of solutions of unconstrained optimization models were analyzed and derived. Then the general form of the model formula was extended to the combined unconstrained optimization model of path selection subject to polynomial Logit and C-Logit. A simple example was used to demonstrate the feasibility and effectiveness of the proposed model. The results show that the solution of unconstrained optimization combination model is equivalent to that of constrained combination model. At the same time, the overlapping effect of path affects the equilibrium travel flow, destination flow, mode flow and path flow through the overlap length of the path and the attraction of the OD pairs. Compared with general models, the proposed model has better explanatory and predictive power.

Key words: traffic engineering, combined model, unconstrained optimization method, C-Logit model, mode choice