Travel time reliability – a comparative assessment of formal and informal public transport in Johannesburg, South Africa

Abstract

Travel time reliability is a transport system performance measure that captures the level of consistency or variability in travel time from origin to destination by any mode of transport. This paper presents an investigation of travel time reliability for the formal Bus Rapid Transit (BRT) and the informal paratransit (minibus taxi) services running on a common corridor in Johannesburg, South Africa. Paratransit and the BRT are two major modes of public transport in major cities in South Africa like Johannesburg. This study employs field collection of travel time data through on-board surveys along bus corridors with parallel BRT and paratransit service. Among the objectives of the investigation is to quantify the travel time reliability of these two modes using a set of reliability indicators proposed by the Federal Highway Administration (FHWA) US Department of Transportation. The study also aims to gain some insight into the critical factors that impact delays and overall travel time for the modes and to propose some measures that could improve reliability. The implication of the measured travel time reliability indicators for overall journey time planning for trip makers and bus operators is also discussed.