Public Transport-Based Crowd-Shipping with Backup Transfers.

This article focuses on a novel last-mile delivery model called the Public Transport-Based Crowd-Shipping with Backup Transfers (PCBP), designed to address the challenges of urban parcel delivery amid rising e-commerce and urbanization. The model integrates public transit as a backbone network, automated parcel lockers, crowd-shipping (CS), and backup transfers (BT) using zero-emission vehicles to provide fast, cost-effective, and environmentally friendly express deliveries. The authors formulate PCBP as a two-stage stochastic program to optimize the locations of public transit (PT) connections and develop a branch-and-price algorithm enhanced by decomposition branching to solve large-scale instances efficiently. Computational experiments and simulations based on Istanbul's railway system and real delivery data from the e-commerce company Trendyol demonstrate that the system can achieve over 96% same-day delivery with significantly reduced vehicle kilometers and emissions compared to current diesel van-based practices. The study highlights the potential environmental, economic, and operational benefits of combining multimodal transport and crowd participation in urban logistics, while noting the need for further research on real-time management and crowd-shipper behavior modeling for practical implementation.