互通立交变速车道长度的探究

在考虑互通立交变速车道建设成本的同时，评价增加变速车道长度对提高互通立交变速车道安全性所带来的经济效益，通过构建效益-成本比（ B/C）分析模型，提出了综合考虑行车安全和建设成本的互通立交变速车道长度设计选用的建议值。研究表明：随着变速车道长度的增加，起初B/C值呈明显增长趋势，达到峰值后，随着长度取值的增加，B/C值开始缓慢下降，将对应的变速车道长，作为变速车道长度设计选用的建议值。

Discussion on Speed Shifting Lane Length of Overpass

In considering shifting lane construction costs , the economic benefits of increasing the length of shift-ing lane to improve safety was assessed .By constructing benefit -cost ratio （B/C） analysis model, the recom-mended value of shifting lane length was proposed based on comprehensive consideration of traffic safety and con -struction costs .The research showed that with the increase of shifting lane length , the initial B/C values shows a growth trend and after the peaking value with the increase of shifting lane length , B/C values slowly decline , the corresponding shifting lane length is selected as the recommended design value .