Service design of shared first- and last-mile transit systems

This paper explores the design and optimization of shared first- and last-mile transit systems (SFLMTS) as an essential component of public transport systems. It addresses the gap between the demand for efficient connectivity from suburban and rural areas to main transit hubs and the current underperformance of traditional public transportation systems in providing comprehensive last-mile solutions in sparsely populated areas. By focusing on demand-responsive transit (DRT) services, this study presents a novel framework for designing SFLMTS that leverages mobility-on-demand (MoD) principles to enhance the accessibility and efficiency of regional and national rail networks. The paper introduces a comprehensive framework that encompasses design and operational decisions, including passenger commitment, trip consolidation, and service-level considerations, which are crucial for optimizing the performance and economic viability of DRT services. Through a detailed case study, the paper illustrates the application of this framework using realistic data and simplified operational models (SOMs), demonstrating the potential of DRT to significantly reduce the number of required vehicles, decrease operational costs, and improve service levels compared to traditional fixed-route services. The findings highlight the importance of strategic design decisions in maximizing the efficiency and sustainability of first- and last-mile transit solutions, offering valuable insights for transportation planners, policymakers, and researchers.