Abstract

Gravel road safety is a crucial area of road safety since gravel roads represent a substantial proportion of the entirety of the nation’s roadway network. Also, gravel roads pose inherent hazards that are otherwise absent in paved roads. Nonetheless, research related to gravel road crash count prediction models, known as safety performance functions (SPFs), was rarely undertaken. SPFs are required for identifying high crash risk locations, or hot-spots, and assessing changes in crash counts before and after implementing safety countermeasures. This research offers a diagnosis of the applicability of the Highway Safety Manual (HSM) to gravel roads in Laramie County, Wyoming. Even though the HSM does not address gravel road safety, the most appropriate methodology, provided by the HSM, for predicting counts of crashes on gravel roads is that of rural two-lane highways. This methodology is applied to Laramie County’s conditions and, as per the results, it is interpreted that the methodology is not applicable to such conditions. Therefore, developing SPFs for Wyoming’s conditions are recommended even though this involves labor hours, expertise and costs. Also, including a chapter in the HSM, devoted to gravel road safety, is suggested.

摘要

碎石路安全是道路安全的一个关键领域，因为碎石路占整个国家道路网络的很大一部分。此外，碎石路会带来固有的危险，而铺砌的道路则不存在这些危险。尽管如此，与碎石路碰撞计数预测模型（称为安全性能函数 (SPFs)）相关的研究很少进行。需要 SPF 来识别高碰撞风险位置或热点，并评估实施安全对策之前和之后的碰撞次数变化。本研究对公路安全手册 (HSM) 对怀俄明州拉勒米县碎石路的适用性进行了诊断。尽管 HSM 没有解决碎石路安全问题，但 HSM 提供的最合适的方法，用于预测碎石路上碰撞次数的方法是农村两车道高速公路。该方法适用于拉勒米县的条件，根据结果，该方法被解释为不适用于此类条件。因此，即使这涉及工时、专业知识和成本，也建议针对怀俄明州的情况制定 SPF。此外，建议在 HSM 中加入专门讨论砾石道路安全的章节。