16.4 Countermeasures for Pavement/Shoulder Drop-Offs Shoulder drop-offs are present where the pavement surface and roadside surface differ in height (from a fraction of an inch to several inches). Height differences typically result from rutting erosion, excessive...
16.2 Passing Lanes The addition of passing lanes on two-lane roads can improve traffic operations and minimize motorist frustration by giving faster-moving vehicles a designated lane in which to bypass slower traffic. Table 16.1 lists design parameters for passing...
15.6 Methods to Reduce Driver Speeds in School Zones Traffic control devices and pavement markings are valuable for encouraging motorists to drive at lower speeds in school zones. Table 15.2 provides operational and design guidelines for school zones. Table 15.2...
14.12 Human Factors Considerations in Traffic Control Device Selection at Rail-Highway Grade Crossings Table 14.2 lists human factors to consider when deciding whether to install a Yield sign, Stop sign, or active control device. A Yield or Stop sign should always...
14.10 Countermeasures to Reduce Gate Rushing at Crossings with Two-Quadrant Gates Gate rushing occurs when a motorist (a) drives under gate arms that are being lowered or (b) drives around lowered gates. Several countermeasures are available to discourage gate...
14.4 Driver Information Needs at Passive Rail-Highway Grade Crossings When only passive warning devices are installed at a rail-highway grade crossing, motorists need good information to determine whether a train is approaching. Verify the following information is...
