Vehicle dispatching with time-dependent travel times

Abstract

Most of the models for vehicle routing reported in the literature assume constant travel times. Clearly, ignoring the fact that the travel time between two locations does not depend only on the distance traveled, but on many other factors including the time of the day, impact the application of these models to real-world problems. In this paper, we present a model based on time-dependent travel speeds which satisfies the ''first-in-first-out'' property. An experimental evaluation of the proposed model is performed in a static and a dynamic setting, using a parallel tabu search heuristic. It is shown that the time-dependent model provides substantial improvements over a model based on fixed travel times.

Minimum cost VRP with time-dependent speed data and congestion charge

“…Ichoua et al [5] introduce a time-dependent model for the vehicle routing problem with time windows based on time-dependent travel speeds which satisfies the First In First Out (FIFO) property. They implement a parallel tabu search approach and test its performance both in dynamic and static environments.…”

The time-dependent vehicle routing problem with soft time windows and stochastic travel times

“…For the VRPTW with time-dependent travel times, the FIFO property is satisfied by Ichoua et al (2003) by means of modeling travel times as continuous piecewise linear functions. The authors solve their model by a procedure based on a parallel TS method.…”

“…Routing customers with respect to a deterministic and static schedule is a strong assumption for reallife environment, leading to inefficient operations. To consider more realistic representations of real-life problems, several adapted versions of the classical Vehicle Routing Problem (VRP) have been addressed, such as stochastic routing problems (see, e.g., Gendreau et al, 1996) and time-dependent routing problems (see, e.g., Ichoua et al, 2003;Van Woensel et al, 2008).…”

Optimizing departure times in vehicle routes

“…The disadvantage of an arbitrary continuous travel time function is that it does not need to be (piecewise) linear. Therefore, we choose to follow the approach of Ichoua et al (2003), who propose a travel speed step function for each link in the network. This approach results in a continuous piecewise linear travel time function.…”

“…Since travel times depend on both distance traveled and time of departure, Malandraki and Daskin (1992) introduce the time dependent vehicle routing problem (TDVRP). Furthermore, Hill and Benton (1992), Ichoua et al (2003), Fleischmann et al (2004), Haghani and Jung (2005), and Van Woensel et al (2008) propose travel time models and algorithms for the TDVRP.…”