01128721

Component

The focus of this paper is an examination of the multiple, potentially conflicting influences of three important elements of traffic assignment modeling: uncertainty, risk and congestion. Uncertainty is the extent to which travelers' route choice remains unexplained in the traffic assignment model; risk refers to travelers' attitudes to travel time, and traffic congestion is of course the mechanism by which route choices feedback into network route costs. In order to facilitate this investigation, we choose to study the simplest model that possesses the key qualitative features we wish to examine, namely the Stochastic User Equilibrium (SUE) model where route travel cost is given by a non-linear transformation of route travel time. Numerical experiments are carried out on two different sized networks, considering the flow-independent and flow-dependent traffic assignment problems. These experiments conclude that the first two elements of our interest directly influence the travelers' sensitivity in their route choice decision. A relationship between these elements is developed in the form of a rescaling factor. Furthermore, it is found that the combined influence of all elements reveals the congestion effect in travelers' route choice dominates the influence of their perceived network costs when the path distillate changes are relatively large for a lower change in the travelers? risk-related behavior.

01120148

09-1836

English

21p

2009

Transportation Research Board 88th Annual Meeting

DVD

Figures (5) ; References (20) ; Tables (2)

Numerical analysis; Route choice; Traffic assignment; Traffic congestion; Traffic flow; Travel behavior; Travel surveys; Travel time; Uncertainty

Stochastic user equilibrium models

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

Transportation Research Board Annual Meeting 2009 Paper #09-1836

TRIS, TRB

Jan 30 2009 6:06PM