01155411

Component

In this paper the authors present a novel methodology to assess travel time reliability in a transportation network, when the source of uncertainty is given by uncertain road capacities. Specifically, the authors present a method based on the theory of Fourier transforms to numerically approximate the probability density function of the system-wide travel time. Except for noted pathological cases, any common continuous or discrete probability distribution can be used to model capacity uncertainty. Theoretical bounds on the approximation errors are formally derived. These bounds provide valuable insights into the structure of the approximation errors and suggest ways to reduce them. From a practical point of view, the authors propose a procedure based on successively refining the computational grid in order to guarantee accurate approximations. The proposed methodology takes advantage of the established computational efficiency of the fast Fourier transform. In a numerical case study, the authors demonstrate that the results of the methodology are consistent with intuition.

01147878

10-1127

English

16p

2010

Transportation Research Board 89th Annual Meeting

DVD

Figures; References; Tables

Fourier transforms; Highway capacity; Probability density functions; Travel surveys; Travel time; Uncertainty

Traffic theory; Travel time reliability

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

Transportation Research Board Annual Meeting 2010 Paper #10-1127

TRIS, TRB

Jan 25 2010 10:30AM