Public bus transportation system network analysis for improved accessibility in a South African city: a case of Durban.

Abstract

A significant goal of developing cities in developing countries, particularly in South Africa, is to develop a sustainable public transportation infrastructure. Significant efforts have made to augment the public transportation system and provide greater accessibility to the people in several major cities in South Africa, including Johannesburg, Pretoria, Cape Town, and Durban. However, the public transport system, involving mainly bus transportation, remains secondary to predominantly private transportation by means of individually driven cars and public transportation by taxis operated by private agencies. Furthermore, the public transportation system has been observed to be under-utilised. It has been argued that the challenges include inadequate route networks, the configuration of the routes, frequency of buses, location of bus stops (nodes), availability of information, social inclusiveness and bus fare, which engender challenges of accessibility. Furthermore, numerous suburbs with a disproportionately lower socioeconomic profile have restricted access to public bus transit. In other words, due to inadequate route networks, the public bus transit system is insufficiently accessible. Therefore, using the study context of the current public bus transportation system of Durban City of South Africa, the factors related to the route network which influence accessibility were examined in this study and how the accessibility of the public bus transportation system could be improved and become inclusive was explored. To achieve this, the spatial design of the current public transport network was evaluated, a network analysis of commuters’ accessibility was performed, the social inclusiveness of commuters using the public bus network was examined, and a model was developed to simulate scenarios that would make it possible to improve the accessibility of the public bus network. A field observation methodology was adopted to collect data about public transport and users. Further spatial and network-related data were collected by using a geographic information system. In addition, the eThekwini Transport Authority provided secondary data on both geographical land use and the public transit network. A geographic information system method was used to make spatial analyses of the public transportation system. The study was conducted using both spatial analysis and statistical methods. Both descriptive and inferential statistical methods were used to examine the relationship between various spatial, public bus transportation network and user factors. Relevant statistical modelling, such as the Negative Binomial Regression Model, was used to examine the influence of various parameters of public bus transportation accessibility on the model. The findings revealed that the suburbs on the outskirts and townships on the city's outskirts lacked proper access to the city's public transit system. This implied that more infrastructure consisting of roads and nodes (bus stops) should be extended to those locations. The findings also confirmed that commuters from these locations combined walking, biking, and using lifts to reach their bus stops. The simulations showed further that positive increments in the parameters of accessibility (Bus usage, Frequency, Cost, walking time and social inclusivity) indicated improvement in the accessibility of public bus transportation, while negative values indicated no accessibility. The study helps to a better knowledge of the numerous accessibility problems that residents in different suburbs of Durban, South Africa's eThekwini metropolis, encounter. The novelty of the study lies in the incorporation of social inclusivity in the public bus transportation accessibility model, specifically in the South African context of Durban. The findings are useful because they may be used to help reconfigure and upgrade the public transportation network in Durban, South Africa, to improve accessibility for individuals living in the city's outskirts. Furthermore, public transportation companies can identify more efficient routes and send more of their vehicles to them. The findings of the study can be utilized to help design policies and strategies for the positioning of bus stops in order to improve people's accessibility, as well as alternative and efficient public transportation routes. In addition, the study used a geographic information system-based spatial methodology with probabilistic modeling to analyze the public transportation route network, providing an alternate method for assessing problems of public transportation accessibility.