Two-lane highways constitute a large proportion of the U.S. highways. An essential component needed in the design of safe two-lane highways is the passing sight distance (PSD). Otherwise, insufficient PSDs lead to passing-related crashes and, therefore, no-passing zones ought to be marked. This research involves the development of a new apparatus of the two-vehicle method, which is used for measuring the PSD in the field. That is to replace the defunct apparatus used by the Wyoming Department of Transportation (WYDOT). To the best of the authors’ knowledge, the introduced apparatus is the most up-to-date system and addresses shortcomings of previous research. The two-vehicle method involves two successive vehicles spaced at a gap, equivalent to PSD, and both vehicles travel at the speed limit. The driver of the rear vehicle operates a switch when the lead vehicle becomes invisible because of sight obstructions, such as vegetation, signaling the beginning point of the no-passing zone. Similarly, the switch is operated when the lead vehicle returns to view to designate the endpoint of the no-passing zone. The apparatus is composed of vehicle-to-vehicle radio communication devices, global positioning system devices, the switch and computers with graphical user interfaces to record and display the data. Testing was conducted on two two-lane highway segments. As per the results, overall discrepancies between WYDOT’s no-passing zone markings and those designated by the apparatus, developed, ranged from 1% to 7%. This research lays the foundation for a future study involving the development of a cutting-edge prototype.

两车道高速公路在美国高速公路中占很大比例。安全的两车道公路设计中需要的基本组件是通过视距（PSD）。否则，PSD不足会导致与通过相关的崩溃，因此，应标记不通过区域。这项研究涉及开发一种新的两车法设备，该设备用于现场测量PSD。那就是代替怀俄明州运输局（WYDOT）使用的废旧设备。据作者所知，所介绍的设备是最新的系统，可解决先前研究的不足。两辆车的方法涉及以间隔等于PSD的间隔连续行驶两辆车，并且两辆车都以限速行驶。当前车由于视线障碍（例如植被）而看不见前车时，后车的驾驶员操作开关，这标志着通行区的起点。类似地，当引导车辆返回观看以指定不通过区域的终点时，操作该开关。该设备由车载无线电通信设备，全球定位系统设备，交换机和带有图形用户界面的计算机组成，以记录和显示数据。测试在两个两车道的高速公路路段上进行。根据结果​​，WYDOT的不通过区域标记与设备指定的标记之间的总体差异为1％至7％。这项研究为未来的研究奠定了基础，该研究涉及开发最先进的原型。