Traffic Engineering (transportation) - Highway Safety

Highway Safety

Highway safety engineering is a branch of traffic engineering that deals with reducing the frequency and severity of crashes. It uses physics and vehicle dynamics, as well as road user psychology and human factors engineering, to reduce the influence of factors that contribute to crashes.

A typical traffic safety investigation follows these steps

1. Identify and prioritize investigation locations. Locations are selected by looking for sites with higher than average crash rates, and to address citizen complaints.

2. Gather data. This includes obtaining police reports of crashes, observing road user behavior, and collecting information on traffic signs, road surface markings, traffic lights and road geometry.

3. Analyze data. Look for collisions patterns or road conditions that may be contributing to the problem.

4. Identify possible countermeasures to reduce the severity or frequency of crashes.

• Evaluate cost/benefit ratios of the alternatives

• Consider whether a proposed improvement will solve the problem, or cause "crash migration." For example, preventing left turns at one intersection may eliminate left turn crashes at that location, only to increase them a block away.

• Are any disadvantages of proposed improvements likely to be worse than the problem you are trying to solve?

5. Implement improvements.

6. Evaluate results. Usually, this occurs some time after the implementation. Have the severity and frequency of crashes been reduced to an acceptable level? If not, return to step 2.