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...
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...
The author of the Highway Safety Manual (HSM) Part B developed a predictive method for safety management. A software tool for highway safety system analysis called the SafetyAnalyst is developed basing on HSM Part B. The author describes an effort to evaluate the feasibility of SafetyAnalyst in Oregon. Seven sample...
A random sample of Oregon motor carriers was selected to determine the effectiveness of the Accident Countermeasures (ACM), a process created to address the factors involved in truck accidents and recommendations a motor carrier may utilize to prevent future similar accidents from occurring. Two groups of fifty motor carriers were...
This thesis evaluates pre-construction auditing procedures used in the United Kingdom, Australia, and New Zealand in order to help create post-construction auditing procedures for the state of Oregon. It was funded as part of the development of the Oregon Department of Transportation (ODOT) Safety Investigation Manual, and also evaluates content...
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...
This thesis presents the procedure adopted to develop the priority rating system for highway safety improvements. Safety hazards are classified into four categories:
(1) Railroad crossings,
(2) Intersections,
(3) Geometric-Related Hazards, and
(4) Roadside Hazards.
For each category of hazards, relationships are developed to obtain a hazard index and expected...
Evaluation of the safety hazards along a highway is usually
performed at specific locations and on known hazards. But, it is also
important to find any unrecognized hazards and their locations. Many
factors contribute to accident potential, and the combined effect of
several of them could produce a hazard that...
Crash rates are said to be nearly three times higher on curved sections than those on straight sections of rural roadways. As a result, advisory curve/speed signs are standard practice to mitigate these risks on sharp horizontal curves. The industry standard for determining appropriate and uniform speeds for such signs...