TY - JOUR
T1 - Finding the most reliable path with and without link travel time correlation
T2 - A Lagrangian substitution based approach
AU - Xing, Tao
AU - Zhou, Xuesong
N1 - Funding Information:
This paper is based on research work partially supported through the Safe Trip 21 project, sponsored by the Research and Innovative Technology Administration (RITA), US Department of Transportation. We would like to thank the California Partners for Advanced Transit and Highways (PATH) in the University of California, Berkeley and NAVTEQ Corporate for providing traffic measurement and map data of the Bay Area, CA. We also want to thank our colleague Mr. Jeffrey Taylor in the University of Utah and the referees for their careful review and comments. The work presented in this paper remains the sole responsibility of the authors.
PY - 2011/12
Y1 - 2011/12
N2 - Path travel time reliability is an essential measure of the quality of service for transportation systems and an important attribute in travelers' route and departure time scheduling. This paper investigates a fundamental problem of finding the most reliable path under different spatial correlation assumptions, where the path travel time variability is represented by its standard deviation. To handle the non-linear and non-additive cost functions introduced by the quadratic forms of the standard deviation term, a Lagrangian substitution approach is adopted to estimate the lower bound of the most reliable path solution through solving a sequence of standard shortest path problems. A subgradient algorithm is used to iteratively improve the solution quality by reducing the optimality gap. To characterize the link travel time correlation structure associated with the end-to-end trip time reliability measure, this research develops a sampling-based method to dynamically construct a proxy objective function in terms of travel time observations from multiple days. The proposed algorithms are evaluated under a large-scale Bay Area, California network with real-world measurements.
AB - Path travel time reliability is an essential measure of the quality of service for transportation systems and an important attribute in travelers' route and departure time scheduling. This paper investigates a fundamental problem of finding the most reliable path under different spatial correlation assumptions, where the path travel time variability is represented by its standard deviation. To handle the non-linear and non-additive cost functions introduced by the quadratic forms of the standard deviation term, a Lagrangian substitution approach is adopted to estimate the lower bound of the most reliable path solution through solving a sequence of standard shortest path problems. A subgradient algorithm is used to iteratively improve the solution quality by reducing the optimality gap. To characterize the link travel time correlation structure associated with the end-to-end trip time reliability measure, this research develops a sampling-based method to dynamically construct a proxy objective function in terms of travel time observations from multiple days. The proposed algorithms are evaluated under a large-scale Bay Area, California network with real-world measurements.
KW - Lagrangian relaxation method
KW - Path travel time reliability
KW - Reliable route
KW - Shortest path algorithm
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U2 - 10.1016/j.trb.2011.06.004
DO - 10.1016/j.trb.2011.06.004
M3 - Article
AN - SCOPUS:80455164690
SN - 0191-2615
VL - 45
SP - 1660
EP - 1679
JO - Transportation Research Part B: Methodological
JF - Transportation Research Part B: Methodological
IS - 10
ER -