Efficient Urban Transit Systems: Bridging Freight Logistics and Passenger Transport

Urban areas face infrastructure capacity challenges because of growing populations and significant contributions from the logistics sector to congestion and emissions; road transportation accounts for 30%–40% of urban traffic and 25%–50% of greenhouse gas emissions. To address these congestion and sustainability challenges, innovative and collaborative solutions are needed for the transportation of passengers and goods. This research presents a system integrating passenger and goods transportation within public-transit networks to enhance efficiency and sustainability. By exploiting underutilized public-transit capacity, this approach aims to reduce vehicle miles traveled while generating additional revenue for transit providers. Named the Freight on Scheduled Bus (FoSB) system, we aim to utilize the unused seats of fixed-route urban transit buses for medium-sized package deliveries. The methodology involves converting bus schedules into a time-expanded graph and solving a multicommodity maximum-flow optimization problem to estimate the number of packages that underutilized bus capacities can serve. We assume that the desired delivery time windows for packages and bus schedules are given. The underutilized capacity of buses is calculated from historical data from automatic passenger count (APC). Various scenarios are analyzed, including bus routes serving central urban areas and suburban areas, and express bus routes. The findings suggest that the FoSB system can reduce underutilized capacity by up to 64% and underutilized capacity-mileage by up to 38.5% on specific routes, significantly contributing to urban sustainability. This research offers insights into managing public-transit capacity and highlights the potential benefits of integrating passenger and goods transportation systems.