Diesel drivers who are “rolling coal” in Colorado: Tune up or pay up

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