Rasmus Dyhr Frederiksen

A Stochastic Route Choice Model for Car Travellers in the Copenhagen Region

The paper presents a large-scale stochastic road traffic assignment model for the Copenhagen Region. The model considers several classes of passenger cars (different trip purposes), vans and trucks, each with its own utility function on which route choices are based. The utility functions include distributed coefficients (Error Components) estimated on SP-data in a mixed logit model. This was compared with a traditional nested logit model. A number of alternative formulations of EC were tested, and the resulting distributions of value of times are discussed. In application, the different classes and types of vehicles influence all the speed-flow relationships on links within an equilibrium framework. Sub-models for intersections and roundabouts describe queues and geometric delays.

Large-scale schedule-based transit assignment – further optimization of the solution algorithms

Nielsen (2004) discussed the design, implementation and optimization of a schedule-based public transit assignment model. Based on this, Nielsen & Frederiksen (2006) improved the model with respect to computation times. The present article describes further development and improvements of this model. The improvements span a wide range of approaches, including optimization of the shortest path algorithm and graph search, reducing the number of stochastic simulations, and making the equilibrium algorithm more efficient. The optimizations techniques were tested on the Copenhagen network in order to reduce the computation times for large-scale networks. Based on this recommendations are given on solution algorithms for schedulebased assignment procedures.