Study area

The City of Johannesburg, presents a number of unique opportunities when compared to other African cities, with the presence of the rapid railway transit system, being Gautrain, as noticeable difference. Since the launch of this train in 2010, it has taken up a larger mode share of trips within the Gauteng province. Also given how the city has invested in infrastructure for bus rapid transit, the integration of these modes of mobility can greatly reduce traffic congestion and improve travel times for commuters.

The Gautrain being a rapid railway transportation system and the Gaubus being an extension of the Gautrain service in the form of a bus rapid transportation system operates across the City of Johannesburg, City of Tshwane and City of Ekurhuleni. The study focused on routes located within the City of Johannesburg, as it is the economic hub of the Gauteng Province with a population of 4.4 million people and a surface area of 1,645km². Currently the Gautrain has 5 operating train stations in Johannesburg:

Park: it serves as a mobility hub connecting the city with other parts of the country and Africa;

Rosebank: it hosts South Africa’s biggest company headquarters;

Sandton: it is currently the fastest growing central business district;

Malboro: it is spatially located at the heart of one of Johannesburg growing townships Alexandra;

Midrand: it hosts the newly developed Mall of Africa which attracts shoppers from all over the African continent.

Given how the train stations are located at areas of economic importance in the city, the Gaubus was developed with currently 15 routes in Johannesburg as an extension of the Gautrain to transport commuters to and from these points of interest (see Fig 7). Currently commuters in Johannesburg have the option to board the Gaubus at their origin points which will take them to the train station to board the Gautrain. The Gaubus route network from Park to Midrand (see Fig 7) can be represented as a tree graph, with the train stations being hubs.

As it can be seen, the Gaubus network has exactly the structure defined in Fig 1. When a commuter wishes to traverse from any bus stop to the Gautrain station, currently he/she only has one option and if the bus network has a failure/shut down at any point in the network the quality and the feasibility of the commuter’s journey will be severely impacted. Therefore, there is a need for a more robust network providing several alternative routes. Creating new motorized routes could have significant economical and ecological costs. The method described in the previous section is applied to create non-motorized routes to enhance multi-modality of the Gautrain network. Typically, to the existing bus routes and stations, the study aimed at adding green mobility services, non-motorized rickshaw services precisely.