Scheduling with mixed fleets to improve the feasibility of electric minibus taxis: A case scenario of South Africa

Abstract

The path to electrification of the informal and organic transport sector – minibus taxis in South Africa’s case – is fraught with challenges. These stem mainly from shorter ranges and slower re-energising of electric vehicles, compounded by their unscheduled nature and day-variant routing. However, the transformation also presents opportunities for improving infrastructure and vehicle utilisation. Planning for electrification becomes a complex spatio-temporal interdependence between mobility, infrastructure (civil and electrical), vehicle specifics, and driver behaviour. This paper evaluates two scenarios using mixed fleet analysis: (1) striving to achieve the same mobility patterns with equal-sized electric vehicles and (2) scheduling for passenger demand, which was extracted from existing mobility patterns. The paper’s main contributions lie in a proposed method to bridge the gap between these two scenarios through trip extraction, as well as introducing the concept of mixed fleets as a way to achieve electrification in the paratransit industry. The results show that using passenger demand to place the charging infrastructure and schedule the vehicles and their charging, results in a reduced number of vehicles, a higher proportion of electric vehicles in the fleet, a reduced number of chargers required, a reduced grid impact, and only a fractional increase in total fleet distance covered. Consequently, we propose to leverage the transformational opportunity presented by electrification to structure sub-Saharan Africa’s paratransit.