Designing microtransit services in suburban areas: A case study in Palermo, Italy

Poor quality of Public Transport (PT) services is one of the main causes of social exclusion for people living in the suburbs. Public transport companies usually allocate few financial resources to these areas, providing transport services with low frequency, poor accessibility, poor reliability, and high waiting times at stops. Recently, microtransit has emerged as an effective solution to improve the travel experience in suburban areas, particularly for non-commuting trips during off-peak hours. This paper presents an integrated methodological approach for designing microtransit services to meet the mobility needs of people living in low-density suburbs. By conducting a Reveled Preference (RP) and Stated Preference (SP) survey and developing a travel demand model, the demand was estimated and used as input to simulate and size the service. Combining GIS and simulation models, Key Performance Indicators (KPIs) were assessed; fleet size to meet the trip requests was identified and the fare was selected using a sensitivity analysis. The method was applied to a real case study to design a new microtransit service with flexible routes and on-demand stops in a suburban area in Palermo, Italy. The results highlight how introducing a microtransit service with 30 nine-seater vans could change the mobility habits of people living in the suburban area, being attractive and financially sustainable if costing 2 €, or just a little more than the existing fixed-route bus service. It could improve the travel experience by reducing the average waiting time at stops to around 5 min and improve access to amenities and PT hubs by guaranteeing a walking time of maximum about 8 min.