Urban Transportation Continuous Equilibrium Network Design Based On Travel Time Budget

Urban transportation network design has been considered as the most hard and challenged problem for a long time. Especially, in huge and complicated transportation network, link improvement or adding new link should be determined under critically calculating. In fact, making a research on urban transportation network design does not only provide an important scientific value, but also benefits transportation practice.Firstly, the importance of the transportation system is summarized, and then the existing condition of the urban transportation system including existing problems and corresponding measures is presented. Meanwhile, the literature review about the last 30 years is made, which covers many models and algorithms. To go on the context, the relative mathematical theories are given simply.This paper discusses link travel time distribution versus path travel time distribution with giving the relationship between them, and then the concept of travel time budget is come up with, while the related theorems and conclusions are developed. The rule of equilibrium assignment which is based on travel time budget is determined, and then the multi-user equilibrium assignment model is established. To prove the equivalence with the actual condition, the existence and uniqueness of the solution, this paper utilizes mathematical optimization theory. At last, a new algorithm is built. In addition, a numerical example is given to validate the feasibility and correctness.According to the context, a bi-level mathematical programming model is given to describe this problem. Reference to Tonbin's research, the sensitivity analysis for the equilibrium assignment model based on travel time budget is made. At last, heuristic algorithm is come up with to solve a bi-level mathematical programming model.