01555316

Component

Understanding of correlation patterns of highway segment travel times is critical to quantifying highway path travel time reliability. However, most existing empirical observations on segment travel time correlations only focus on a small number of neighboring segments, and the general correlation patterns between multiple segments along a long highway path are yet to be investigated. This paper conducts an empirical study to analyze how travel time correlation between two arbitrary segments along a long highway changes with the distance between these two segments. The authors analyze a series of consecutive microwave detectors along an express way in Beijing, China. The travel time of a segment covered by two neighboring detectors is estimated with the speed counts at these two detectors. Pairwise correlation coefficients of all segment travel times were calculated. The authors discover a profound pattern in these pairwise correlations: the correlation magnitude in general decreases with the distance between the two corresponding segments and the decreasing trend follows a power law function. This discovery reveals a fundamental relationship that links segment travel time measurements (which are easy to obtain from existing traffic sensors) with path travel time distributions (which is difficult to measure or estimate), and thus provides an empirical basis for travel time reliability modeling.

This paper was sponsored by TRB committee ABJ30 Urban Transportation Data and Information Systems.

01550057

15-5624

English

16p

2015

Transportation Research Board 94th Annual Meeting

Digital/other

Figures; References; Tables

Distance; Microwave detectors; Reliability (Statistics); Spatial analysis; Speed; Statistical analysis; Travel time

Beijing (China)

Data and Information Technology; Highways; I72: Traffic and Transport Planning

Transportation Research Board Annual Meeting 2015 Paper #15-5624

TRIS, TRB, ATRI

Dec 30 2014 1:53PM