Guidelines for the provision of bypass roads at and through-ways in cities and towns

Abstract

Roads provide linkages between cities and towns, neighbouring countries, and to other points of interest. Up until the mid-20th century, roads forming part of the national network in South Africa generally passed through cities and towns. As these areas grew and traffic volumes increased, it became clear that bypasses would be necessary. In 1960 the National Transport Commission adopted its freeway policy which included the concept of bypass roads. Despite the adoption of the concept of bypass roads, the provision of these roads remained a controversial issue. The perceived benefits to the city or town of through traffic are weighed up against the benefit of a bypass to long-distance traffic in terms of travel time and cost, and road safety considerations. The aim of the paper is to provide guidelines for the planning and management of bypass roads and through-ways, as well as for the economic impact analysis of these roads. The paper refers to Christaller’s Central Places Theory which explains the spatial distribution of a system of cities and towns, as well as the road network linking these centres with one another. The assessment of the need for a bypass road is then addressed. Guidelines are provided on aspects such as land use development, road network planning, and route determination principles. An economic analysis framework, addressing both social cost-benefit analysis and economic impact analysis methodologies, is presented. Finally certain conclusions are reached. The paper is based on a research project, Project P2.5 of 2018: “Provision of bypass roads and through-ways in settlements, towns and cities”, conducted as part of the SANRAL Research Programme.