Don’t be caught by surprise. A new traffic law goes into effect in Colorado on January 1. You can only use the left lane of a highway to pass another vehicle.

Starting Jan. 1, troopers will stop warning drivers and start issuing $35 tickets, plus a $6.20 surcharge and three points on their license. A six-month-old law says the left lane is to be used only for passing on any of Colorado’s multilane highways where the speed limit is 65 mph or faster. Lawmakers passed the bill, hoping to prevent traffic congestion and cut down on road rage. If a highway has three or more lanes, motorists are expected to stay out of the far left lane.

There will be an exception for rush hour.