Selection of vehicle size and extent of multi-drop deliveries for autonomous goods vehicles: An assessment of potential for change

Abstract

This paper examines how vehicle size and multi-drop deliveries may change as a result of the removal of the driver cost for autonomous goods vehicles. Analysis is conducted by combining parameters derived from transport economics and vehicle engineering for a series of increasingly complex applications, ultimately incorporating a unique vehicle routing problem formulation for two multi-destination applications. It is concluded that while the removal of the driver cost produced the greatest savings, the use of smaller vehicles and fewer deliveries per journey could produce incremental savings, dependent on the application. The incremental savings and potential change in vehicle sizes and number of deliveries was greatest for applications: 1) where the human driver would otherwise constitute a greater proportion of overall cost (such as urban deliveries), 2) where there is greater dispersion of delivery locations relative to the origin depot, 3) where the value of the cargo time is higher. For a UK customer deliveries case study currently using 3.5 t vans, a shift to smaller 2.1 t vans performing 40–60% fewer stops per route could lead to an additional 7–16% of cost savings, or up to 75% savings when combined with the direct driver cost savings. By contrast, for a UK supermarket distribution case study using 44 t articulated trucks, the introduction of some 26 t rigids serving fewer stops per route indicated effectively negligible potential savings compared to the 22–32% of savings due to the removal of the driver. Conclusions are conditional on treating a number of aspects of the logistics system as fixed in order to isolate factors of interest. Realistically, such aspects may be subject to change in future scenarios under the combined impact of autonomous freight vehicles and other trends.