17.2 Behavioral Framework for Speeding Factors related to the motorist, vehicle, road, and environment influence speeds at which motorists drive. Figure 17.1 reviews factors designers should focus on to select countermeasures that mitigate speeding. It is critical to...
16.8 Design Consistency in Rural Driving Motorists make fewer errors when they encounter geometric features that are consistent with their expectations. Inconsistent designs or facility operations violate driver expectations. Expectations for downstream road segments...
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...
13.12 Determining Work Zone Speed Limits Decisions about work zone speed limits need to account for road geometrics and the location of work zone features (e.g., lane closure tapers, work activity). If possible, keep work zone speed limits within 10 mph of normal...
13.8 Changeable Message Signs The purpose of changeable message signs is to communicate important messages succinctly. Keep display messages to a maximum of two phases. Avoid splitting information across phases, use a consistent format for calendar dates, and make...
