山区高速公路立交出口匝道区域可变限速研究

基于山区高速公路立交出口匝道区域线形指标偏低、气候变化频繁的特点，在限速管理上，提出“匝道动态限速，主线联动限速”的可变限速策略。匝道的限速值是依据车辆横向稳定性和停车视距两个约束条件，并考虑路面附着系数和道路能见度的动态变化特性进行确定。主线受出口匝道影响路段的限速值是依附匝道圆曲线路段限速值和实际减速车道长度进行确定。在参数取值的探讨中，区分了纵向附着系数和横向附着系数的不同影响。研究成果可以为山区高速公路的运营安全管理尤其是限速管理提供借鉴。

Variable Speed Limit for Off-ramp Region of Mountain Highway Interchange

Based on the features of poor geometry and labile climate in mountain expressway interchange off-ramp regions, this paper proposes a variable speed limit management strategy called“dynamic speed limit on ramp and linked speed limit on mainline”. The speed limit value on ramp was formulated based on vehicle lateral stability and stopping sight distance,in which road adhesion coefficient and road visibility were considered. The speed li-mit value on mainline section affected by off-ramp was linked with the speed limit value on ramp and actual length of the deceleration lane. The difference between lateral adhesion coefficient and longitudinal adhesion coef-ficient was discussed. This research provides a reference for mountain highway operation safety management espe-cially for speed limit management.