The Research On Roadside Hazard Rating Evaluation For Mountain Highways

Over the past decade, with the rapid development of China’s road construction mileage, road traffic safety has become an increasingly prominent social problem and research focus. The related statistics show that in the record of serious traffic accidents, most of they were involved in the roadside hazards. According to incomplete statistics, the number of roadside accidents occupies about1/3of road traffic accidents, and the proportion of casualties caused by the roadside accidents was significantly higher than the proportion of roadside accidents’number. Facing to the urgency of roadside risk evaluation and the demand of roadside protection theory, although some domestic experts proposed some related evaluation methods, it is still difficult to get rid of the dilemma:rely heavily on the subjective experience of the expert scoring, and lack of the necessary objective basis and technical support. As for the reasons, it maybe the lack of in-depth investigation and research the security situation and the detailed characteristics for mountain roadside, as well as our long-term oversight of the road accident statistics database’building.This paper carried out a statistical analysis on the survey results of dangerous roadside points in domestic mountain area, found out the influencing factors of the roadside risk, and built a comprehensive evaluation model of the roadside hazard raring. The model consists of3main parameters:the roadside encroachment frequency, the probability of roadside crash after encroachment, and the accident severity.4categories of influencing factors were considered, such as the geometric characteristics of the highways, the traffic flow characteristics, the geometric characteristics of the roadside, and the typical roadside hazards, which can properly reflect the level of the roadside hazard rating. To calculate one of the most important indicator, the crash severity of the roadside hazards, the paper used crash simulation technology to build the vehicle-roadside hazard crash simulation models, and selected the occupant injury indicators, Acceleration Severity Index (ASI), to quantify the crash severity of roadside collisions. Referring to the Ministry of Transportation’former research and standards, and taking into account the operability of the classification number and the ease of use in practice, the paper divided the roadside hazard rating into four classes. The higher level represents that the roadside condition is more dangerous. Finally, the paper used the above3parameters to construct the roadside hazard rating evaluation model. The example analysis of the model shows that the model can accurately assess the actual roadside risk. The grading standards and evaluation methods of the roadside hazard rating proposed in this paper provide a workable reference standard for domestic roadside risk (safety) evaluation, and also provide the basis for the degree of the roadside protection and the selection of the protective equipments, which contributes to reduce mountain roadside accidents, save the cost of the highways’ security projects, and assign the limited security resources reasonably.