特殊条件下隧道内设置拓宽变速车道长度研究

山区高速公路受地形影响,很多互通式立交的设置位置受到很大限制,导致隧道出口与互通式立交出口之间间距很小。根据隧道内车辆驾驶人员对隧道内标志的识别、辨识、认读,以及车辆变换车道所需距离等条件,考虑对某些处于特殊条件的隧道设置1个变速车道,以缩小隧道出口与互通式立交出口之间的距离。分析结果表明,在设计速度为80 km/h的高速公路2级服务水平下,隧道出口处拓宽变速车道的长度不宜小于309 m,一般宜大于310m。在设计速度为60 km/h的山区高速公路隧道内拓宽变速车道的最小长度为203 m,一般应大于210 m。满足以上条件时,可以在隧道出口处设置变速车道以减少隧道出口与互通式立交之间的间距。

Research on Length of Broadened Speed-change Lanes Set in Tunnels under Special Conditions

Due to influence of geography on mountainous expressways,the set positions of many interchanges are limited greatly,leading to very small space between tunnel exits and interchange exits.In accordance with conditions such as recognition,identification and reading of drivers in tunnels for marks in tunnels and the distance required for vehicle to change lanes,etc.,this paper considers to set one speed-change lane in some tunnels under special conditions to shorten the distance between tunnel exits and interchange exits.The results of analysis indicate that at grade 2 service level of expressways at design speed of 80 km/h,the length of the broadened speed-change lane at the exits of tunnels should not be less than 309 m and in general should be more than 310 m.In mountainous expressway tunnels at design speed of 60 km/h,the min.length of the broadened speed-change lane should be 203 m and in general should be more than 210 m.If the above conditions are satisfied,the speed-change lane can be set at the exits of tunnels to reduce the space between tunnel exits and interchange exits.