by\u00a0J\u00e9r\u00e9mie Voumard, Olivier Caspar, Marc-Henri Derron and Michel Jaboyedoff: \u00a0“Dynamic risk simulation to assess natural hazards risk along roads”.<\/p>\n
Risk generated by natural hazards on roads is usually calculated with equations integrating various parameters\u00a0related to hazard and traffic. These are static variables, like\u00a0an average number of vehicles crossing this section every day\u00a0and an average vehicle speed. This methodology cannot take\u00a0into account dynamic variations of traffic and interactions\u00a0between vehicles such as speed modifications due to windy\u00a0roads, slowdowns resulting from saturated traffic or vehicle\u00a0tailbacks forming in front of traffic lights.\u00a0Here we show, by means of a dynamic traffic simulator,\u00a0that traffic variations may greatly influence the risk estimation over time. The risk is analysed on several sections of\u00a0an Alpine road in Switzerland using a dynamic vehicles approach, and compared with the results of the static methodology. It demonstrates that risk can significantly increase on\u00a0sinuous sections because of decreasing vehicle speed. For example, along an 800 m-long section of road containing two\u00a0hairpin bends, the dynamic risk is about 50 % higher than\u00a0the static one. Badly placed signalization, slowing down, or\u00a0stopping the vehicles in a hazardous area may increase the\u00a0risk by about 150 % (i.e. 2.5 times higher) along a straight\u00a0road section where vehicles speed is high.\u00a0A more realistic risk can thus be obtained from a dynamic\u00a0approach, especially on mountain roads. The dynamic traffic simulator developed for this work appears to be a helpful\u00a0tool to support decision-making in reducing risk on mountain roads and it shows the importance of keeping the traffic\u00a0moving as freely as possible.<\/span><\/p>\n