Abstract

In 2014, the authors successfully developed local calibration factors (LCFs) for the rural and urban arterials and highways for the State of Maryland. In this research, the authors computed LCFs for freeway segments, speed-change lanes, and signalized and stop-controlled ramp terminals to complement and complete LCFs for Maryland to adjust predicted motor vehicle crashes as part of the Highway Safety Manual (HSM) application. Implementing the HSM requires local calibration or development of jurisdiction-specific models. Either one is a laborious and challenging process because, despite being explained in the manual, the process is not easy or straightforward. Thus, the main contribution of this article is providing a detailed case study of the most complete calibration effort with the HSM Supplement models. Furthermore, the current state of the HSM Supplement adoption by different states is discussed. The results of the conducted research are summarized including the LCF development procedure and challenges that the authors had to overcome as well as some suggestions. LCFs were computed for data from a three-year study period (2008–2010) from multiple resources of Maryland government agencies. Ramps and collector-distributor (C-D) roads were excluded due to insufficient historical crash data. Baltimore City was also excluded because of a different data collection scheme.

摘要

2014 年，作者成功地为马里兰州的农村和城市主干道和高速公路开发了局部校准因子 (LCF)。在这项研究中，作者计算了高速公路路段、变速车道以及信号灯和停车控制匝道终端的 LCF，以补充和完善马里兰州的 LCF，以调整预测的机动车碰撞，作为高速公路安全手册(HSM) 应用程序的一部分。实施 HSM 需要本地校准或开发特定管辖区的模型。任何一个都是一个费力且具有挑战性的过程，因为尽管在手册中进行了解释，但该过程并不容易或直接。因此，本文的主要贡献是提供了使用 HSM 进行最完整校准工作的详细案例研究补充模型。此外，讨论了不同州采用HSM补充的现状。总结了所进行的研究的结果，包括 LCF 开发过程和作者必须克服的挑战以及一些建议。LCF 是根据来自马里兰州政府机构的多种资源的三年研究期（2008-2010 年）的数据计算的。由于历史事故数据不足，坡道和集配电 (CD) 道路被排除在外。由于不同的数据收集计划，巴尔的摩市也被排除在外。