Abstract: In order to improve the intelligence level of route selection of mountainous highway, the analysis on highway route selection decision auxiliary model was conducted on the basis of the improved A* algorithm. Firstly, the plane constraint indexes and vertical cross-section constraint indexes for highway route selection were proposed. Then, according to the actual situation of mountainous highway route selection, the traditional A* algorithm was improved in terms of valuation function, search range, search direction, data structure, optimization methods, etc., and the highway route selection decision auxiliary model was established. Finally, the validity of the proposed model was confirmed through case study. Research results show that compared with the traditional A* algorithm, the improved A* algorithm reduces search time by about 75%, search iterations by about 48%, and the number of search nodes by about 44%. The total turning angle and length of the route after optimization are reduced by about 83% and 17%, respectively. The highway route selection decision auxiliary model is capable of effectively addressing the route selection problem in complex natural environmental conditions and possesses high practical value.

Key words: highway engineering; highway route selection decision auxiliary model; improved A* algorithm; mountain route selection; route selection constraint index

摘要： 为提高山区高速公路选线的智能化水平，基于改进A*算法对高速公路选线决策辅助模型进行了分析。提出了高速公路选线的平面约束指标和纵断面约束指标；根据山区高速公路选线实际情况，从估价函数、搜索范围、搜索方向、数据结构、优化方法等方面对传统A*算法进行了改进，建立高速公路选线决策辅助模型；并通过实际案例验证了该模型的有效性。研究结果表明：与传统A*算法相比，改进A*算法在搜索时间、搜索次数、搜索节点数方面分别降低了约75%、48%、44%；路线优化后的总转折角度和长度分别降低了约83%和17%；高速公路选线决策辅助模型能有效地处理自然环境复杂条件下的选线问题，具有较高的实用价值。

关键词: 道路工程；高速公路选线决策辅助模型；改进A*算法；山区选线；选线约束指标