As Wyoming braces for winter, the Wyoming Department of Transportation (WYDOT) is carrying out tests of new semi-automated variable speed limit signs (VSLs), with the aim of rolling out the technology across the state on New Year’s Day 2023. The new innovative speed limit system will automatically adjust the speed limit indicated on the signs, using data from electronic sensors. Vince Garcia, WYDOT’s Intelligent Transportation Systems Program Manager, said the new speed limit signs are meant to respond to the frequently changing Wyoming weather and make driving safer for people.
“We are trying to make sure that we do the best job of lowering and raising the speeds so that they are appropriate for the winter conditions”, Garcia said. “The pilot is to just work out any kinks. We are doing a pilot program between Laramie and Rawlins on Interstate 80, and also on Wyoming 28, that’s commonly known as South Pass. We will roll it out by January 1st on all eight variable speed limit sections across the state.”
While the technology can adjust speeds automatically, Garcia said it also requires a human element to account for unforeseen circumstances.
“The automation still has a human component. Speed limit changes prompted by the program can be adjusted or even vetoed by a boots-on-the-ground employee like a trooper or highway maintainer,” said Garcia. “For example, if sensors indicate traffic can resume normal interstate speeds, but there is an active crash investigation and cleanup in the area, troopers can hold the lower speed to protect first responders and keep the traveling public safe”. In the past, the department has faced criticism from the public over the adjustments of the variable speed limit signs. Garcia said the new innovation is responding to these complaints.
“It’s relatively easy to reduce the speeds, but it's more complex to increase the speed after a storm has passed,” he said. “We have received some legitimate criticism about the way we raise the speeds, and we are trying to address those. The intent is for this to be kind of a pilot so we learn from the mistakes that we will obviously make.”
WYDOT sensors adjust the speed indicated on the VSLs when employees may not be in the area to initiate the changes themselves. This results in quicker speed adjustments, which can match how quickly conditions change on Wyoming highways. So if a snowstorm is happening, the speed limit would decrease, and increase after the snowstorm.
