A preliminary prototype of a computerized accident risk assessment tool for freight transport by road in Finland has been constructed based on a concept developed in an earlier stage of a study project. The tool is based on real data on the road network, traffic flows and injury accidents. The estimates of accident risk are based on Bayesian models and take into account both accident frequency and severity. Variations in accident risk according to time of year, day of week, time of day, vehicle type, road type and road surface conditions are taken into account in the risk models. The output from the tool includes the probability of an injury accident and the expected numbers of persons injured or killed within a journey or journeys required to deliver a given amount of cargo from one place to another by the transport means and route as specified by the user. An interactive graphic user interface with map applications is provided to support routingand planning of the transports in the network model. The preliminary prototype is currently developed further by extending the risk assessment to cover also rail and sea transports, by including also injury accidents in the loading and unloading of cargo in the risk estimates, and by improving the graphic user interface by employing interactive map applications to support routing and planning of transports in the network models. As a result, the final prototype tool will be applicable to freight transports by road, rail or water, as well as to multimodal transportations combining these. The risk of accidents in the transhipments and other handling of goods within a specific transport assignment will also be considered. The main motivation for the risk assessment approach and the associated prototype tool development has been to supplement the traditional, accident statisticsbased reactive views of traffic and transport safety with a risk based proactive approach considered more suitable for the needs of transport planning and management, both strategic and operational. The development work has been funded by the Ministry of Transport and Communications of Finland.In the paper we will describe the overall concept as we have specified itfor freight transport risk assessments, and explain how it is used in therisk assessment prototype tool. We will also discuss the various difficulties that were faced in the study with respect to modelling of freight transport accident risk, and the implications these difficulties have had in the adapted approach, and on how it has been implemented in the prototype tool. For the covering abstract see ITRD E135582.
Abstract