Integrating Vehicle Routing and Scheduling

Background:

The economic, environmental and social costs of road freight transport vary by time of day and day of the week. Sustainability could be enhanced if the planning of delivery operations took more account of the variability of external costs over daily, weekly and seasonal cycles.

This work module will examine this issue from two standpoints. Firstly, it will attempt to refine the tools that companies use to optimise vehicle routing and scheduling by incorporating estimates of the average speeds that can be achieved on particular road links at particular times, given prevailing traffic conditions. Using vehicle tracking data contributed by a commercial service provider, we plan to develop a prototype vehicle routing and scheduling system which can plan schedules for different types of distribution operations in order to minimise the time-based costs. This will be applied to a range of distribution scenarios to determine potential savings and sustainability benefits. An assessment will also be made of the utility of time-specific vehicle routing and scheduling software in helping companies to adapt delivery operations to different road charging options.

                                          Figure. % of HGV-kms run between 8pm and 6pm.

Secondly, the work module will examine the opportunities that companies actually have for modifying delivery schedules and the associated logistical cost trade-offs they have to make. Opportunities for rescheduling deliveries are constrained by the need to synchronise transport with production and distribution operations, particularly in low-inventory supply chains. Little research has been undertaken to assess the degree of flexibility in these supply chains and the logistical cost trade-offs that companies would have to make in rescheduling deliveries, for instance to night-time. Such flexibility will condition the industrial response to time-variable road charges. We will examine the interaction between delivery scheduling and the scheduling of production, warehousing and retailing activities to assess the degree of operational flexibility and cost implications of retiming deliveries for different types of supply chain operations.

Figure. HGV traffic distribution by time of day on all roads        

Thus, the main objectives of this module are to:

1. To refine the tools that companies use to optimise vehicle routing and scheduling by incorporating estimates of the average speeds that can be achieved on particular road links at particular times, given prevailing traffic conditions
2. To test this prototype against a range of scenarios
3. To examine the opportunities that companies actually have for modifying delivery schedules and the associated logistical cost trade-offs they have to make, particularly in low-inventory supply chains.