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...
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...
13.10 Sign Legibility Factors that influence sign legibility include retroreflectivity, color, letter/number font, and location (e.g., roadside or overhead). Prismatic sheeting enhances sign retroreflectivity. Use of fluorescent colors increases sign visibility in...
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...
13.2 Overview of Work Zone Crashes Young male motorists (ages 25 – 34) are most likely to be involved in work zone crashes. Knowledge of work zones and how they influence safety is valuable for reducing crash risk. Table 13.1 provides general guidance on structuring...
11.8 Countermeasures for Improving Accessibility for Vision-Impaired Pedestrians at Signalized Intersections Several design strategies can be used to improve accessibility for vision-impaired pedestrians at signalized intersections: Avoid the use of large-radius...
