Traffic safety is a serious concern on the Dalton Highway, a 414-mile road in Alaska, one of the most remote, and the sixth most dangerous highway in the world. Half of all vehicle crashes on the Dalton occur during daylight hours, while fully a quarter of the crashes occur at night where the vehicles are travelling on non-lighted sections of the road. Inclement weather with blowing snow and whiteout conditions necessitate marking the shoulders as a safety feature to navigate this important remote highway.
Pexco LLC partnered with the Alaska DOT to develop a new design of delineator that would improve visibility for DOT workers and truck drivers as well as reduce maintenance for the agency.
The solution was the new Dalton Delineator, a cantilever structure consisting of a short length of a Davidson Flexi-Guide FG 400 Roadside Delineator post mounted to a special flexible coupler. The coupler in turn is attached to a square steel tube support that is installed off of the traveled roadway. The delineator post - or "arm" - projects horizontally out from the shoulder, above the roadway; is capable of rebounding when struck; and provides excellent reflectivity at night.
Creating the Delineator
In the Spring of 2009, the Alaska DOT contacted Pexco to ask for help in designing an improved delineator to improve safety on the Dalton Highway. The DOT had previously had good success with the durability of Pexco’s Flexi-Guide FG 400 Roadside Delineator post through the harsh Alaskan winter. They asked Pexco to develop a flexible coupler to mount the impact resistant post to an overhead cantilevered squared steel tube structure.
Using their knowledge of plastics, Pexco developed a square reinforced polyurethane tube that is attached to the delineator and then slipped into the tubular steel cantilever. When the delineator arm is impacted, the flexible polyurethane tube allows the arm to deflect and then return to the proper position. Materials for both the arm and the coupler were chosen for their UV-stability and their cold temperature impact performance.
The last part of the solution was the use of white delineator arms on one side of the road and green delineator arms on the opposite side. Similar to the running lights on a boat, this color coding gives drivers clear indication of their position on the road, even in the midst of a blinding snowstorm.
In the summer of 2011, installation of these new delineators began along a 200-mile-long section, providing enhanced visibility for maintenance crews and users of the Dalton Highway.
Key Features & Benefits of the Dalton Delineator on the Alaskan Highway
- Engineering thermo-plastic provides extreme-cold impact resistance
- Elevated steel arm reduces chance of damage during snow plow operations
- Flexible polyurethane coupler simplifies installation and removal
- Bright colors provide for color-coded road edge identification
