“Cross the line, pay the fine” is the warning from the Colorado Department of Transportation.

The technology to detect when drivers weave in and out of express lanes is coming to the central I-70, I-25 South Gap and U.S. 36 corridors beginning Dec. 1, according to a news release.

CDOT said its common to see drivers cross over the solid white lines into the express lanes when traffic slows or when trying to get around another vehicle already in the express lane. Vehicles may only enter or exit express lanes at points clearly designated with signs and dashed lines, said department officials.

The system uses sensors, cameras and software that work together to identify vehicles that are weaving in-and-out of toll lanes and was deployed for the first time on the I-70 mountain corridor in June 2023. It has since been expanded to the C-470 and North I-25 express lanes, according to CDOT.

“This technology has already reduced violations by 80% in the corridors where we’ve deployed it,” said Tim Hoover, a CDOT spokesman. “This means accidents avoided and lives saved.”

In 2022, the Colorado Legislature passed HB22-1074, allowing the Colorado Transportation Investment Office to enforce Colorado express lanes rules using advanced roadway technology.

Drivers weaving over the solid lines between express lanes and the general-purpose lanes cause crashes each year. Due to the speed differentials between vehicles in the express lanes and those in the general-purpose lanes, this behavior significantly increases crash risks, according to CDOT.

Drivers in all lanes do not anticipate cars suddenly crossing over solid lines in front of them, forcing them to react quickly to vehicles moving at different speeds. Vehicles should only enter or exit express lanes at clearly marked points with signs and dashed lines.

“More than 90% of drivers using express lanes follow the rules and don’t cross the solid lines. Unfortunately, the small percentage that do weave endanger themselves and everyone else,” said Hoover. “Starting Dec. 1, we’re giving these drivers 30 days’ notice to change their behavior. After that, if you cross the line, you pay the fine.”

Civil penalties for violating the express lane rules start at $75 if paid within 20 days. After 20 days, the fine increases to $150.

To learn more, visit expresslanes.codot.gov.