Operating speed is one of the best performance measures that can tell transportation agencies how well or how poorly the transportation system is functioning. Fluctuating operating speeds often mean there is a design flaw or something about the physical road design that violates drivers' expectations. A primary example of this...
Isolated approaches at signalized intersections with posted speed limits of 45 mph or greater generally experience large numbers of rear-end and angle collisions. A combination of less attentive drivers, high operating speeds, and less than ideal intersection characteristics can result in crash frequencies well above expected rates. A number of...
Roundabouts have become an alternative for traditional intersections due to the safer operational performance. Previous research has provided crash modification factors (CMFs) as a criterion based on before-after studies as to evaluate the safety performance of roundabouts. One drawback of assessment based on crash modification factors, however, is that a...
Posting advisory speed signs at sharp horizontal curve locations is a common practice in the U.S. These signs recommend drivers safe speeds to negotiate such curves. Literature indicates that adherence to advisory speeds is, in general, poor. Moreover, limited research is available that quantifies safety implications of these signs. This...
Normal acceleration characteristics of passenger cars provide valuable information for various aspects of transportation engineering, including use in the geometric designs of intersections, freeway ramps, passing lanes, acceleration lanes, turning bays, or in the development of traffic
simulation or fuel consumption models.
However, the data used in previous studies are...
In ¬¬¬¬2009 the Federal Motor Vehicle Safety Administration (FMCSA) conducted the “Safety Belt Usage by Commercial Motor Vehicle Drivers Survey” for the National Highway Traffic Safety Administration (NHTSA). The survey found that, nationally, 74% of commercial truck drivers wear their safety belts at all times. In the western region of...
Numerous research efforts have proven the safety benefits of access management. There are several access management techniques, including unsignalized access spacing, signalized intersection spacing, left-turn lanes, right-turn lanes, Two-Way Left-Turn lanes (TWLTLs), nontraversable median, U-turns, interchange access separation distances and so on.
This project explores the correlation between access density...
Posting advisory speed signs at sharp horizontal curve sites is a practice well established in the United States. The purpose of these signs is to provide the driving public with a safe speed to negotiate such curves; however, the link between these signs and safety has not yet been clearly...
An intersection, due to its vehicle and pedestrian conflict movements, experiences complex traffic situations that might contribute to crashes. In the city of Corvallis, OR, historically more than 80% of the total crashes have occurred within an intersection or have been designated as intersection-related. It is important to develop a...
Driving simulation is widely accepted as a safe, effective, and economical alternative for investigating driver behavior in a variety of contexts. However, in order to apply simulator-based research results to real-world settings, the performance measures acquired through simulated driving experiments must first be validated. This research was aimed at validating...