Colorado to switch on data-fueled speed limit signs

Colorado transportation officials said they hope their new variable speed limit signs will help make roadways safer.
variable speed limit sign
(Getty Images)

The Colorado Department of Transportation plans on Tuesday to switch on a new feature of speed limit signs installed along a 10-mile stretch of Interstate 70.

Officials said the signs will display variable speed limits that depend on several variables, including weather, the level of traffic congestion and traffic speed. A local NBC affiliate reported that the signs were installed in 2022, but selecting their output based on environmental data has only been in a testing phase until this week.

The stretch of road selected is a mountainous eastbound traversal through the Colorado mountains between Georgetown and Idaho Springs. Officials said the ability to dynamically change speed limits could make the roads safer.

“I think this will help decrease rear-end incidents,” Idaho Springs Mayor Chuck Harmon told 9News. “You have a sunny day like today, and you think, ‘Well surely, I can go 65. There couldn’t possibly be a danger ahead.’ What you don’t know is just a quarter mile ahead there’s a backup with people barely crawling.”


According to the U.S. Department of Transportation, variable speed limit signs can reduce all crashes by 34% and can reduce rear-end crashes by 65%.

In addition to variable speed limit signs, Colorado is also one of dozens of states testing other new technology along roadways with the aim of improving traffic flow and reducing collisions. Colorado in 2022 expanded its connected-vehicle infrastructure, installing 150 devices that can receive data and send messages to the dashboards of passing vehicles.

A map maintained by the U.S. Department of Transportation shows that similar technology deployments are being tested across the country.

Colin Wood

Written by Colin Wood

Colin Wood is the editor in chief of StateScoop and EdScoop. He's reported on government information technology policy for more than a decade, on topics including cybersecurity, IT governance and public safety.

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