There has recently been a stream of research dedicated to the combined use of walking and driving for home on-site services Inspired by actual parcel delivery operations in London, a new paper describes a two-echelon distribution system that combines the use of driving and walking as part of last-mile deliveries in urban areas for a single driver.
A combined driving and walking delivery system could be a viable alternative to last-mile delivery problems in urban areas to mitigate the adverse effects of more traditional means of distribution, such as traffic congestion and the use of kerbside space.
The paper presents an optimization model that explicitly treats and integrates the driving and walking elements, and describes a branch-and-cut algorithm that uses new valid inequalities specifically tailored for the problem at hand. Computational results based on real instances obtained from a courier operating in London are presented to show the performance of the algorithm.
Source: Martinez-Sykora, A., McLeod, F., Lamas-Fernandez, C., Bektaş, T., Cherrett, T., & Allen, J. (2020). Optimised solutions to the last-mile delivery problem in London using a combination of walking and driving. Annals of Operations Research, 1-49.