Those traveling on Interstate 70 who may pass people using the express lanes, or drive in the lane when it’s closed, will soon be held accountable, according to a news release from Colorado Department of Transportation.

Beginning Wednesday, June 21, both westbound and eastbound drivers who improperly use the I-70 Mountain Express Lanes will get warnings. Violations include using lanes when closed, weaving across the solid yellow lines and driving in the lanes with an oversized vehicle.

“These violations are not only dangerous, they are illegal,” said Tim Hoover, a CDOT spokesperson, in the release. “We want motorists to arrive at their destinations safely, and we want to send a message that life-threatening bad behavior will not be tolerated.”

The warnings will extend for a 30-day grace period. Beginning July 21, travelers will be fined for violations.

Fines will begin at $75 for a first offense but will increase to $150 if not paid within 20 days of receipt. The penalties will eventually apply to all Express Lanes in Colorado, but enforcement will primarily focus on the mountain express lanes, which stretch from Idaho Springs to U.S. 40.

A “sophisticated, first-in-the-nation technology system that includes sensors, cameras and software will be used to identify those who use the lanes improperly, according to the news release.

“This technology is a game-changer,” Hoover said in the release. “It will not only help us identify and penalize drivers who are endangering themselves and others, we truly believe it will help save lives and make our roads safer for everyone.”