Toll concessions: management strategy and deflection performance of the N3TC network in South Africa

This paper discusses the N3 Toll Concession’s approach to optimise management of the road network during the Concession Period and to achieve the end of Concession requirements. To be able to achieve this, accurate traffic and performance data is essential. On the N3, traffic is continually measured on the network, and the condition and performance in terms of rutting, roughness, surface texture and deflections is measured annually. Deflections are considered to be a good indicator of the structural capacity of pavements, and are expected to increase with time and traffic carried. This assumption underlies many available pavement design methods. This paper shows that for 22 representative sections on the N3 Toll Route, the deflections do not increase with time or traffic within the periodic maintenance periods. This leads to the conclusion that the use of deflections as an indication of remaining structural capacity for the heavy duty N3 pavements in conventional pavement design analysis is not appropriate.