The Colorado Department of Transportation is reminding commercial vehicle drivers that as of Sept. 1, commercial vehicles weighing more than 26,000 pounds and traveling Interstate 70 between Dotsero (mile 133) and Morrison (mile 259) must carry sufficient chains along this segment until May 31, 2013.

"We've had instances when snow's fallen in the high country in September, so we want commercial vehicle drivers to be in compliance with the 'must carry' chain requirement and be prepared for winter-type road conditions, even at this early date," said CDOT Region Transportation Director Tony DeVito. "We have lots of chain stations as well as other programs to assist drivers during the winter months."

Colorado's chain law was enacted in 1996. It applies to all interstate, federal and state highways. It includes two levels for commercial vehicles:

Chain Law Level 1 requires all single drive axle combinations commercial vehicles to chain up. All four drive wheels must be chained; cables are not permitted as an alternate traction device. All other commercial vehicles must have snow tires or chains. Level 1 may be implemented any time there is snow covering any part of the traveled portion of pavement on an ascending grade.

Chain Law Level 2 requires all commercial vehicles to chain up. Auto transports must comply to the extent possible without causing damage to hydraulic lines. Buses must chain two drive wheels to comply. Level 2 may be implemented any time there is snow covering the entire traveled portion of pavement on an ascending grade or when driving conditions dictate this level is necessary to protect safety and minimize closures.

The alternate traction control device known as the and click on the green cell phone icon in the upper right-hand corner below the search function and select the appropriate items under Commercial Vehicles or other areas of traveler interest.

Road condition and chain law information also is accessible at or by calling 511.