17.12 Speeding Countermeasures: Communicating Appropriate Speed Limits Motorists purposefully or inadvertently driving over the speed limit increases crash risks. Despite motorists failing to comply with speed limits in many situations, it is important to clearly...
17.8 Effects of Posted Speed Limits on Speed Decisions Researchers have found that most motorists exceed posted speed limits. Motorists exceed speed limits for several reasons: (1) they believe speeding carries little risk; (2) they usually drive at what they perceive...
17.6 Effects of Roadway Factors on Speed Geometric, environmental, and traffic-related variables all influence driving speed under free-flow conditions on tangents. Drivers of free-flowing vehicles can select speeds based on their level of comfort and the appearance...
17.4 Speed Perception and Driving Speed Motorists can misperceive the speed at which they are traveling. Although speedometers indicate vehicle speed, often motorists rely on external cues (e.g., engine noise, vibrations, visual sensations elicited through highway...
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...
