Risk Assessment for Road Safety Evaluation on Two Lane Rural Highways

S. Cafiso and G. La Cava (Italy)


Risk assessment approaches and methodologies, Road Safety, Road Safety Inspections, Ranking criteria


Road safety evaluations on two-lane rural roads with low/medium traffic flows can raise concerns both due to the general deficiency of reliable data on road accidents and to the circumstance that few crash data due to low traffic not always can give enough information on accidents distribution and causes. Based on these considerations, an original methodological approach for Risk assessment of two-lane rural highway is presented. The proposed model uses analytical procedures referring both to Road Safety Inspection and to alignment Design Consistency models. A Safety Index (SI) that quantitatively measures the relative safety performance of a road segment is defined and the procedure to carry out numerical values is presented. SI is formulated by combining three components of risk: the exposure of road users to road hazards, the probability of a vehicle being involved in an accident and the resulting consequences should an accident occur. The procedure has been validated comparing the results obtained by SI formulation with real world crash occurrence. A good agreement between SI values and expected number of crashes has been observed. The SI has two main applications. Risk assessment is useful to identify and to rank by the SI score high-risk segments. Specific safety issues, that give more contribution to unsafety, are pointed out by their safety index in order to give indications regarding more appropriate mass-action programs.

Important Links:

Go Back