![]() ![]() Consequently, long tunnels and bridges are replacing long roadways in mountainous freeways. ![]() This is because tunnels and bridges can not only traverse complex terrains within a short distance but also help improve traffic efficiency and reduce air pollution they are becoming more common owing to modern construction technologies and lower construction costs. Similarly, bridges and tunnels constitute 63% of the Chongqing section of the Yuxiang freeway, which has a total length of 270 km. For example, the Ankang section of the Xihan freeway, which has a total length of 78 km, has a bridge and tunnel ratio as high as 70%. Mountainous freeways with high bridge and tunnel ratios are becoming more prevalent in the middle and western regions of China owing to the rapid improvement in the economy and the implementation of the national freeway network improvement plan. The findings shed some light on the road design and traffic management implications for strengthening the traffic safety of mountainous freeways. The annual average daily traffic and driving adaptability were found to be related to crashes. The crash severity on bridges and bridge groups was significantly higher than that on the other types of road sections, being mostly attributed to single-vehicle crashes. The crash rates were found to be the highest in interchange and service areas, lower in ordinary sections, and the lowest in tunnels, being mostly attributed to collisions with fixtures. The results demonstrate the applicability and validity of this method. Actual data were analyzed to investigate the crash patterns in an entire freeway and in each special section through statistical and comparative research. The traffic-influence areas of elementary and composite structures were proposed and defined. In view of the various structures and differences in the driving environments, a scenario-based discretization method for such a road was established. The crash characteristics of the road are still unclear, but it also provides conditions for studying how various road environments affect traffic. Mountainous freeways with high bridge and tunnel ratios are a new type of road that rarely contain many special road sections formed by various structures. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |