TDR³: Time-dependent routing of regenerable resources

Asvin Goel

It can be expected that road freight transport in the European Union will increase by around 50% until 2050. As possibilities of expanding the road infrastructure are limited, it can be expected that this growth in road traffic will increasingly lead to traffic congestion and travel times along some routes will increasingly depend on the traffic situation. Timely deliveries are becoming more and more important because of increasingly synchronised supply chains with low inventory levels. If time-dependent travel times are ignored when planning vehicle routes, frequent delays and the need for buffer times will be the result. From an economical point of view, both delays and unnecessary buffer times should be avoided. From an ecological point of view, we will see that electric vehicles, and also battery-powered vehicles, will gain importance in road freight transport. Due to a limited range of battery-powered vehicles and because of the long time required to charge batteries, it will be indispensable to plan ahead when the vehicles shall be recharged. From a societal point of view, we can expect that road safety and working conditions of truck drivers shall steadily improve and thus, compliance with hours of service regulations will be increasingly expected and enforced. Both the remaining operating range of battery-powered vehicles and the remaining driving time subject to hours of service regulations can be interpreted as attributes of regenerable resources. Periods in which the resource can regenerate must be scheduled frequently enough that the resource can be utilised without having attribute values outside the feasible operating range. Because of the above mentioned developments both time-dependent travel times and the de- and regeneration of resources must be considered when planning routes and schedules. The overarching goal of this research project is to develop models and methods allowing transport service providers to tackle the above mentioned economical, ecological, and societal challenges. The main scientific questions and algorithmic challenges arise from the interplay between time-dependent travel times and the de- and regeneration of resources, because the FIFO assumption that is typically made in the literature on time-dependent travel times, i.e. the assumption that an earlier departure implies an earlier arrival, can no longer be made. The main scientific goals are to answer the resulting questions and develop methods for routing and scheduling regenerable resource under consideration of time-dependent travel times.
It can be expected that road freight transport in the European Union will increase by around 50% until 2050. This growth in road traffic will increasingly lead to traffic congestion and travel times along some routes will increasingly depend on the traffic situation. This research project, funded by the German Research Foundation (DFG) aims to develop models and methods allowing transport service providers to tackle the economical, ecological, and societal challenges that arise due to this increase, with a particular focus on planning routes and schedules for regenerable resources, such as battery-powered vehicles.

Road freight traffic in the European Union can be expected to increase by around 50 % until 2050. The main goals for this project are to answer the resulting questions and develop methods for routing and scheduling regenerable resource under consideration of time-dependent travel times. The main scientific questions and algorithmic challenges arise from the interplay between time-dependent travel times and the de- and regeneration of resources, because the first in, first out (FIFO) assumption that is typically made in the literature on time-dependent travel times, i.e. the assumption that an earlier departure implies an earlier arrival, can no longer be made. Synchronized supply chains with low inventory levels makes timely deliveries more and more important. If time-dependent travel times are ignored when planning vehicle routes, frequent delays and the need for buffer times will be the result. From an economical point of view, both delays and unnecessary buffer times should be avoided. From an ecological point of view electric vehicles, and also battery-powered vehicles, will gain importance in road freight transport. It will be indispensable to plan ahead when the vehicles shall be recharged. From a societal point of view, we can expect that road safety and working conditions of truck drivers shall steadily improve and thus, compliance with hours of service regulations will be increasingly expected and enforced. Both the remaining operating range of battery-powered vehicles and the remaining driving time subject to hours of service regulations can be interpreted as attributes of regenerable resources. Because of the above mentioned developments both time-dependent travel times and the de- and regeneration of resources must be considered when planning routes and schedules.