Abstract
This paper addressed the vehicle routing problem (VRP) in large-scale urban transportation networks with stochastic time-dependent (STD) travel times. The subproblem which is how to find the optimal path connecting any pair of customer nodes in a STD network was solved through a robust approach without requiring the probability distributions of link travel times. Based on that, the proposed STD-VRP model can be converted into solving a normal time-dependent VRP (TD-VRP), and algorithms for such TD-VRPs can also be introduced to obtain the solution. Numerical experiments were conducted to address STD-VRPTW of practical sizes on a real world urban network, demonstrated here on the road network of Shenzhen, China. The stochastic time-dependent link travel times of the network were calibrated by historical floating car data. A route construction algorithm was applied to solve the STD problem in 4 delivery scenarios efficiently. The computational results showed that the proposed STD-VRPTW model can improve the level of customer service by satisfying the time-window constraint under any circumstances. The improvement can be very significant especially for large-scale network delivery tasks with no more increase in cost and environmental impacts.
Highlights
Urban freight distribution/delivery usually leads to traffic congestion, safety concerns, air pollution, and high logistic costs [1]
Numerical experiments were conducted on the urban transportation network of Shenzhen, China, consisting of 3,454 nodes and 4,876 (2) Stochastic Time-Dependent Link Travel Times of the Network Calibrated by Historical Floating Car Data
In order to test the effectiveness of the approach we proposed, another TDVRPTW test was conducted as the reference in the same instances
Summary
Urban freight distribution/delivery usually leads to traffic congestion, safety concerns, air pollution, and high logistic costs [1]. In urban transportation system, lots of random factors, such as uncertain traffic volume, severe weather conditions, and incidents, can lead to the uncertainty of travel times during most of the day, especially during the morning and evening peak periods. Those nonrecurrent events can significantly affect the reliability of the transportation system and contribute to a stochastic timedependent (STD) congested transportation network. Urban route designs that ignore these significant variations and uncertainties of travel times are often found to be inefficient within a congested traffic condition and may contribute to higher operational costs or inferior customer service [1].
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
