The case involves a man who was injured in a motor vehicle accident. He had just gotten on the highway and was traveling in a lane that merged from two lanes down to one. As he was merging, he hit a large pothole which caused his front tire to go off the edge of the road. When the driver corrected to get back onto the road, he overcorrected, came across the center line, and struck another vehicle head-on. The man suffered a traumatic brain injury and was unable to return to work for 8 months. An expert in highway design and engineering was sought to opine on the surfacing of the roadway.
Question(s) For Expert Witness
- 1. Please describe your experience in highway design and/or engineering.
- 2. What goes into consideration into the design with regards to the shoulder?
- 3. What could have been done to stabilize the shoulder and/or prevent the shoulder from washing out?
Expert Witness Response E-127381
I have been involved in all aspects of traffic engineering (design, operations, maintenance, highway road design, cross sections, etc) since 1965. Most drivers are not equipped to know how to recover from that much of a dropoff. Typically, drivers turn one way to correct the issue when they should really turn the other and they end up overcorrecting. To prevent this, the shoulder should have minimal dropoff. I would want to know what kind of car the individual was driving and I would want to know the maintenance practice of the highway and how recently maintenance was performed. I would also be interested to know if this was a situation where someone else had previously reported the problem. There are two factors that are considered in designing highway shoulders. One is maintenance practice, the other is the cross slope design. Typically, there should be a 2% cross slope on the shoulder and the shoulder should always be brought up to the level of the pavement when it is compacted.