Highway with curved arrow on yellow warning sign

Location
Highway 101 California

Project size
SpeedCheck® radar speed signs, advisory signs and flashing beacons

Client
California Department of Transportation (Caltrans)

 

Overview

Along California’s North Coast, U.S. Highway 101 passes through the giant redwood forests. During the tourist season this meandering “Redwood Highway” is packed with distracted tourists unfamiliar with the roadway, often driving oversized motor homes and campers—a dangerous combination.The likelihood of entering one of this highway’s many curves at too great a speed is very high, resulting in many accidents.

To improve safety and reduce the number of accidents along the route, the California Department of Transportation (Caltrans) instituted a comprehensive solution in two trouble spots—the curves just south of the bypass and the Big Lagoon curves.

The Solution

Caltrans installed SpeedCheck® driver feedback displays, flashing beacons, and static curve warning signs with the posted advisory speed. They also changed to open-graded pavement to provide better skid resistance and quicker drainage during wet weather. The results were very encouraging. In the first year, both locations showed a significant drop in the number of collisions over the previous two years. Near the bypass, the number dropped by 37 percent, while at the Big Lagoon curves, the number was reduced by an astonishing 75 percent.

How it Works

  • Drivers approaching two dangerous curving stretches along the Redwood Highway first encounter an enormous curve ahead sign with the advisory speed prominently posted.
  • Next they see their current speed displayed in bright 18-inch LED digits on a SpeedCheck YOUR SPEED display.
  • If they are traveling too fast for the curve, the SpeedCheck radar triggers flashing beacons and flashes the digits displaying their current speed. The higher the speed, the faster the digits flash.
  • Beyond the display, chevron arrow signs draw attention to the sharpness of the curve

Near the bypass, the number dropped by 37 percent, while at the Big Lagoon curves, the number was reduced by an astonishing 75 percent.

Measurable Results

The use of the MUTCD static signs provides familiarity to the driver while the vehicle activated flashing lights and display of their speed personalizes the importance of slowing down. The heightened awareness of curves ahead and seeing their speed flashing gets drivers to slow down.

Reduction in Collisions chart