Abstract: At approximately 10:25 a.m. on April 11, 2006, four people were involved in a traffic accident while working on a paving project. Employee #1 was employed by Better Roads, Inc. He was operating a Ford F-700 flatbed truck equipped with an illuminated traffic directional device mounted above its cabin and an Energy Absorption Systems, Inc., energy-absorbing system (attenuator) mounted to the rear of the vehicle. In front of him in a Ford F-150 pickup truck were three other people. They were Employee #2 and two coworkers, representing a mixture of private and state workers. The first coworker and Employee #2 were sitting on the lowered tailgate of the pickup truck, and the second coworker was driving the pickup truck. The pickup truck was hauling a rolling straight edge on its hitch ball. The workers were detecting depressions and elevations on a newly paved road, US Highway 27, within the city of Palmdale, Florida. Both vehicles were traveling at approximately 5 miles per hour while their work was being conducted. The posted speed limit on the road was 65 miles per hour. The four-lane highway they were on was divided by a grass median between the two southbound and two northbound lanes. For some reason, an International semi-truck traveling on the left lane of the northbound four-lane highway changed lanes and began traveling northbound on the right outside lane, where the flatbed truck and the pickup truck were measuring the surface of the newly paved road. The semi-truck impacted the attenuator carried by the flatbed truck and pushed the flatbed truck in a clockwise direction onto the grass shoulder at the right (east) side of the road. The flatbed truck came to a rest on the east side of the grass shoulder with its front pointing in a southeasterly direction. Employee #1 was killed. Employee #2 and her coworker, seeing the semi-truck heading toward them, got off the tailgate of the pickup truck and began running on the grass shoulder on the east side of the road. The front of the semi-truck ran into the rolling straight edge and the pickup truck. The semi-truck rotated to the right, dragging the rolling straight edge, which became detached from the hitch ball of the pickup truck. The semi-truck jackknifed and traveled onto the east side of the grass shoulder. The left side of the semi-truck struck both Employee #2 and her coworker, causing incapacitating injuries to Employee #2 and nonincapacitating injuries to the coworker. The semi-truck came to final rest on the east grass shoulder with the front of the truck pointing in a southeasterly direction. The trailer of the semi-truck remained attached to the semi-truck and came to a final rest across the left and right lanes of the highway's northbound lanes with its end pointing toward the southwest side of the road. Employee #2 came to a final rest on the right grass shoulder lying near the rear left wheel of the semi-truck. Her coworker came to final rest on the east side of the grass shoulder farther away from the rear wheel of the semi-truck. The pickup truck came to a final rest on the east grass shoulder pointing in northerly direction. Employee#1 sustained a fracture in his chest and died at the scene of the accident. Employee #2 sustained multiple fractures. She was air lifted to the Lee Memorial Hospital in Fort Myers, Florida, where she was hospitalized. Her injured coworker was transported via ground ambulance to the Florida Hospital in Lake Placid, Florida. The driver of the pickup truck was not injured. There was no mention of any injuries to the driver of the semi-truck.