Climate change and urban road transport - a South African case study of vulnerability due to sea level rise

The focus of this investigation was the impact of predicted sea level rise on the road transportation network of the eThekwini Municipality, South Africa. The main objective was to identify the areas within the municipality which are most vulnerable to sea level rise and to develop adaptive responses and interventions in order to maintain road functionality. For the identification of the most vulnerable areas a multi-criteria analysis supported by geographical information system modelling was used. Three areas were identified, namely, the Isipingo, Bayhead and the Umgeni mouth areas. Adaptive road responses have been researched by employing a network analysis of each of the areas identified. Parameters modelled were traffic volume changes, travel time and volume to capacity ratio - for the main roads in the areas identified. The adaptive responses required for each area were found to be different, varying from the addition of a lane to changes in signal settings. Overall this study presents a model of how vulnerability and the development of adaptive strategies to sea level rise could be addressed by municipalities.