Analytical modelling of a stop-less modular bus service with an application to charging strategies comparison

Abstract

Buses are a vital component of metropolitan public transport, yet conventional bus services often struggle with inefficiencies including extended dwelling time, which increases in-vehicle travel time for non-alighting passengers. A stop-less autonomous modular (SLAM) bus service has emerged as a solution, enabling dynamic capacity to reduce dwelling time. Meanwhile, the electrification of buses is advancing as a strategy to mitigate greenhouse gas emissions and reduces operators' costs, but introduces new operational constraints due to charging requirements. This study develops analytical optimization models for SLAM bus service that integrates vehicle-to-vehicle (V2V) charging technology. By comparing the optimal designs and their feasibility across non-charging case and charging strategies, we identify a sequence of operational stages as ridership grows: from idle capacity under low demand, to full small buses, full large buses, and a proposed frequency-capped regime where only bus capacity expands. Under the mobile charging strategy, this progression further includes an energy-limited regime, in which frequency declines, and ultimately infeasibility under high demand. These findings enable operators to deliver more efficient services.