The N2 collapse at Bot river:regional impact on traffic patterns and lessons learnt for resilience

Abstract

Unprecedented rainfall in 2023 in the Western Cape led to numerous severe flooding events. Heritage Day (24 September 2023) saw a cut-off low system hit the southern regions of the Western Cape, with particularly heavy rain over the Overberg District along the southern coast. A section of the N2 between Caledon and Grabouw, 90 km from Cape Town, was washed away by the Bot River causing significant disruption to long weekend traffic and of course longer-term impact on traffic using this important national route. The road re-opened on 31 October 2023, 36 days after the flooding incident. This paper aims to evaluate the traffic impact caused by the worst flooding event seen in recent years in the Western Cape, provide an historical record of the response by SANRAL to get vehicles back on the N2, and consider lessons learnt for emergency response road construction, considering resource procurement. This paper will evaluate the traffic impact of the full closure of the N2, considering the impact of traffic redistribution to alternative routes as far away as the N1. Floating Car Data are used as the primary source of data in a unique application of this widespread data.