Colorado is riding hard on diesel truck drivers who “roll coal,” the politically charged display of power on the roads that has doused other vehicles, such as environmentally friendly Priuses, and pedestrians, including supporters of presidential candidate Hillary Clinton, with sooty black smoke.

Gov. John Hickenlooper this week said he’ll gladly sign into law a bill lawmakers passed that lets police hit offenders with $100 fines.

“Coal rolling is a cruel cut to people with asthma or other respiratory issues,” Hickenlooper said. “We are well to be rid of it.”

Over the past three years, the practice emerged as a way to have fun at the expense of other people, and air quality that is already compromised in parts of Colorado. Diesel pickup truck drivers illegally tweak their engines — tampering with pollution controls and enabling intake of extra fuel — so that by stepping on their accelerator pedals they can blast out spectacularly foul fumes.

New Jersey has outlawed rolling coal.

But Colorado lawmakers, facing anxieties in agricultural areas, wrestled with legislative proposals and twice killed them before passing the bill this month. Police had pushed for a law that could let them crack down. The police occasionally have been targets of the smoke, Fort Collins Police Lt. Craig Horton said.

“We have problems with that display of exhaust, especially on our weekend nights when we have a cruising issue,” Horton said.

Among those embracing the crackdown is Dana TePoel, owner of Lake Arbor Automotive & Truck in Westminster, who for 25 years has conducted state-mandated emissions tests on diesel vehicles for license renewals. Of 52 tests done on diesel vehicles this past week, seven failed.

About a dozen of the trucks that fail emissions tests at his shop each year have engines altered for rolling coal and are usually brought in by drivers new to Colorado.

“We tell ’em they have to fix it,” he said, noting that the modifications can cost thousands of dollars and that coal rollers who fail emissions tests typically must turn back to people who made the illegal modifications to undo them.

TePoel called the $100 fines “a good addition to the system of prevention, emissions testing, that is already in place.”

Trouble hit rolling coal drivers along Colorado’s Front Range when outdoor restaurant patrons and pedestrians complained. Fort Collins police initially tried to use anti-drag racing laws that allow cops to pull over drivers for exhibitions of speed and power, a jailable offense. Police also found it was hard to enforce existing laws prohibiting tampering with pollution control devices.

State Rep. Joann Ginal. D-Fort Collins, was among those smoked. And last fall, when a line of people formed at the New Belgium Brewery to see a campaign event featuring former President Bill Clinton, Ginal said, plume-producing trucks hit them hard.

Hickenlooper’s signature cannot come too soon, she said.

A few days after she and Sen. Don Coram, R-Montrose, secured final passage of the bill, Ginal was driving in Fort Collins behind a tan pickup truck with Texas license plates. The driver smoked her. Ginal said she had a feeling her state lawmaker license plates made her a target.

“They do it to people in Priuses, people on motorcycles, and people just walking down the streets. Some are older people who have chronic respiratory conditions. The smoke makes it worse,” she said.

“It is mean. It is more young people who are doing this,” she said. “They think it is funny.”

It happens statewide, Coram said, citing incidents in Grand Junction and Durango.

A pregnant woman walking with a small child in Durango was hit, said Coram. She called his office to complain. Rolling coal isn’t a matter of political expression, he said.

“It is people just being jerks,” Coram said.

Ginal introduced legislation in 2016 that died, and tried again this year. Her first bill failed as opponents, including Sen. Jerry Sonnenberg, R-Sterling, a rancher, raised concerns that a crackdown on coal rolling could lead to California-style emission standards for work trucks.

Coram revived the legislation, removing references to harassing behavior — which complicated enforcement — and inserting exceptions for commercial and agricultural vehicles.

Ginal said she expects lawmakers in other states will follow Colorado’s lead.