Post-covid shifts in bus passenger trip timing and vehicle utilisation in Cape Town

Abstract

Golden Arrow Bus Services’ ridership in Cape Town has now recovered to pre-pandemic levels, but a shift in trip timing behaviour has been observed. The purpose of this paper is to explore the nature and extent of this shift, and to consider its impacts on fleet deployment efficiency. Passenger boarding data, from a sample of weekdays before and after COVID-19 movement restrictions, are analysed. Data on peak and off-peak fleet deployment, and on the cost of a bus in service per weekday, are used to develop a rudimentary cost allocation model. It is found that the portion of weekday passenger boardings occurring in peak periods declined by 10.5% after lockdown (and by 5.8% in the peak hour), resulting in a reduction of the peak-to-base ratio from 13:1 to 10:1. It is estimated that fixed costs heavily outweigh variable costs during periods of low demand (fixed costs account for 89% of the cost of system-wide service provision in the midday off-peak hour). Because the peak scales fixed costs, a small reduction in the peak-to-base ratio is found to register a discernible cost efficiency improvement in vehicle fleet utilisation. The number of buses required to service peak demand reduced from 1 124 to 1 040 (a 7% decrease), and the number of buses servicing the off-peak expanded from 200 to 245 (a 22% increase). It is estimated that a 1% decrease in the peak-to-base ratio led to a 0.2% decrease in the daily system-wide service provision cost.