01333486

Component

The speed limit of 55 mph (88 km/h) is typically used on rural highways in the U.S. For locations where curbs are installed along these roadways, some transportation agencies have suggested the use of a lower 45 mph (72 km/h) speed limit because, according to AASHTO, running into curbs at high speeds may cause significant vehicular damage and even severe injuries. However, it has also been argued that lowering the speed limit after the installation of curbs may cause confusion in drivers, who do not perceive the risk associated with the newly installed curbs and tend to operate their vehicles at the same speed as before. To better understand driver behavior on two-lane rural highways before and after curb installation and with different speed limits, researchers at the University of Tennessee conducted a series of experiments on a high-fidelity driving simulator. The scenario matrix consists of several dimensions including posted speed limit (45 and 55 mph, or 72 and 88 km/h), curb installation, lateral clearance between the edge of travel lane and the curb (2ft, 6 ft, and no-curb, or 0.6 m, 1.8 m, and no-curb), weather (clear and fog), visibility (day and night) conditions, traffic conditions in opposing lane (1400 veh/hr and 400 veh/hr), etc. For each subject under different experimental scenarios, detailed driving parameters, such as driving speed and vehicle position in the travel lane, were recorded and analyzed subsequently. Results of the study suggest that driver behaviors are influenced by the various factors in a complex and interrelated manner. It is likely that drivers do not perceive the risk from the curb or actually perceive more risk from the opposing traffic in determining their speed or lane position. In addition, the available space between the curb and the opposing traffic is crucial and has significant impact on driving behaviors.

01329018

11-3926

English

19p

2011

Transportation Research Board 90th Annual Meeting

DVD

Figures (5) ; Photos (3) ; References (23) ; Tables (3)

Automobile drivers; Behavior; Curbs; Driving simulators; Highway safety; Risk assessment; Rural areas; Speed limits; Two lane highways; Weather

Highways; Operations and Traffic Management; Safety and Human Factors; I73: Traffic Control; I83: Accidents and the Human Factor

Transportation Research Board Annual Meeting 2011 Paper #11-3926

TRIS, TRB

Feb 17 2011 6:41PM