It took two tries this legislative session, but Colorado lawmakers on Tuesday voted to ban “rolling coal,” the practice of modifying a diesel car or truck engine to spew unfiltered exhaust.

Senate Bill 278, sponsored in the House by Fort Collins Democrat JoAnn Ginal and in the Senate by Durango Republican Don Coram, passed a final reading in the House today by a wide margin, 40-25.

This is the second version of the bill this year. The first version was killed in a Republican-controlled Senate committee by members who thought the proposed law might net agricultural workers and freight haulers and lead to stricter general vehicle emissions laws. The new version made the behavior and type of vehicles targeted by the law more explicit.

Rolling coal has caught on as a form of defiant cultural protest in the era of climate change and emissions-free vehicles. Drivers pass unsuspecting cyclists and electric car drivers on the road and unleash clouds of toxic black smoke. Coal rollers often post videos of themselves in the act.

The Colorado bill would make rolling coal a traffic infraction and subject drivers to a $100 fine.

Colorado will join New Jersey as the only states that have outlawed the practice. The Garden State banned coal rolling in 2015. A New Jersey citation carries a $5,000 fine.

As many opponents of the bill have pointed out, altering a vehicle’s emissions system to release pollutants is already a federal crime. But traffic officers have to go “smoke school” to train in identifying and citing coal-rolling lawbreakers, so the federal law is rarely enforced.

Dan Grunig, executive director at Bicycle Colorado, told The Statesman weeks ago that making rolling coal illegal as a matter of state law in Colorado would have positive effects.

“The important thing is that the bill would give law enforcement a tool to address the danger,” Grunig said, adding that traffic citations would create data from which to map the phenomenon.

“This concerns tourism, too,” he said, citing state statistics that show cycling tourists spend $317 million in Colorado every year. “Rolling coal sends the message that our roads are unwelcoming.”

The bill now heads to the governor’s desk for a signature.

— john@coloradostatesman.com