Quantification of the natural variation in traffic flow on selected national roads in South Africa

Abstract

Transport and traffic movement is complex and ever-changing. The movement of people and the means by which they travel are directly influenced by the transportation systems available to them. Engineers have the responsibility to provide safe, efficient and economical transportation services, and in order to do this, have to understand the variable nature of traffic. Numerous variations in traffic patterns exist due to the continuously changing movements of people. This study aims to quantify these variations to provide engineers with the tools to understand existing traffic conditions and to allow effective future planning and design. Various types of traffic variations exist, including: variation of traffic over a single day (hourly variation), a week (daily variation), between months of the year (monthly variation), and the annual growth of traffic (annual variation). These variations are analysed using data from 18 counting stations across South Africa. Modification Factors are introduced to quantify the traffic variations. Modification Factors are generated for each type of traffic pattern, providing a tool to understand the variable nature of traffic. This research was conducted at Stellenbosch University as the final year research dissertation of the main author towards the degree BEng (Civil).