Travel time reliability assessment of public transport : a case study of the Johannesburg bus rapid transit (brt) corridors

Abstract

Travel time reliability is one of the key measures of transport network performance. It also provides an indication of the level of predictability of travel time from origin to destination for any mode of transport. This paper presents an investigation of the travel time reliability of the Bus Rapid Transit system in Johannesburg - the Rea Vaya Bus service. The study method involves field collection of travel time information through onboard surveys along the BRT corridors. Travel time reliability is measured using a set of indicators proposed by the Federal Highway Administration (FHWA) of the US Department of Transportation. Among the objectives of the study is to gain some insight into the critical operational and road network factors that impact travel time for both peak and off-peak periods. Some of the factors considered include commuter boarding and alighting delays, stop frequency and delays at intersections. From the study, one of the notable factors found to currently affect travel time reliability for the BRT system was additional delays from traffic signal disruption due to the ongoing load-shedding scheme implemented by the national power agency, ESKOM.