Research On Road Capacity Resulting From Pavement Distress

With the continuous improvement of motorization, urban infrastructure is developing rapidly. As the expansion of urban areas, urban road mileage and density also will increasing rapidly. However, influenced by the vehicle load, weather conditions, etc., coupled with the problems of design methods, processes, construction quality and lag conservation, urban pavement distress become very common. The quality of the road influence the traffic quality. In daily life, people did not cause enough attention to the hazard and losses caused by pavement distress. Driving comfortability has been an important service quality indicators provided by the road, and the pavement conditions seriously affect the quality of driving comfortability. Generally, the road maintenance, repair and evaluation of pavement distress has been the work of pavement maintenance aspects. As the prevalence of pavement distress, combined with road testing and maintenance, repair work not promptly, vehicle traveling on the pavement distress conditions has been common. Current research of the pavement distress mainly on the point of road maintenance. But in actual project, it is also necessary to consider the effects of pavement distress to the traffic operation status, especially the capacity of the road. This paper attempts to establish contact pavement distress with traffic operation status. Then, analyse, calculate the effects of pavement distress to the road actual capacity. For this reason, this paper carried out the following research.Firstly, through the research of the classification and assessment of pavement distress, we point out the deficiencies of existing methods and redefine the pavement distress on the point of traffic operation. We put the pavement distress into two forms: damage extent and effective width of driveway. And both qualitative and quantitative division of each form are given. Finally, we put out the analysis of the locations that pavement distress probably occurred according to its characteristics.Secondly, Based on the data of road damage geometry and driving speed, considering the factors of damage extent and effective width of driveway, we redefine the function of pavement distress extent on the point of traffic operation, and then get the relationship between damage extent and vehicle speed. Subsequently, we analyse the character of driving behavior when driving on the damage region, putting the process of vehicle acrossing damage position into three stage:deceleration, through, acceleration. At last, we establish the driving behavior model and then check the validity of the model, giving the paramater of the model.Finally, this paper construct pavement damage simulation program, according to the vehicle behavior modeling. Then, the paper analyse traffic flow characteristics on damaged road, and then get out the actual capacity under different extent of pavement distress. The results showed that with the increase of pavement distress extent, the actual road capacity decreased. In the same extent of pavement distress condition, the road with higher desire speed has higher actual capaicy. In condition of the same desire speed, the road with more serious pavement distress extent has lower actual capacity. Under the road slightly damaged condition, the impact on road capacity is small. With the increase of pavement distress extent, the impact begin to intensify. Under the road seriously damaged condition, the road actual capacity is significantly reduced. At last, for the sake of practical application, we get the capacity correction coefficient of pavement distress on different extent of pavement distress, undering different desire speed condition.