Starting Sept. 1, all commercial vehicles traveling on I-70 in Colorado between milepost 133 (Edwards exit) and milepost 259 (Morrison exit) must carry sufficient chains to be in compliance with the Colorado chain law.

The law requires commercial vehicles to carry chains on this segment of I-70 from Sept. 1 to May 31.

"Colorado's first snowfall can hit at any moment in the higher elevations and we don't want commercial vehicle drivers to be caught off guard," said Colorado Department of Transportation Region Transportation Director Tony DeVito.

Colorado's chain law applies to all state, federal and Interstate highways and was initially enacted in 1996. 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.

To help ensure that commercial vehicles have a safe location to chain up or down, CDOT has 21 chain stations along the I-70 west corridor, many of which have been improved over the last several years and provide more parking and a safer environment. Truck drivers are advised to watch for yellow signs indicating exact chain station locations.

The 11 chain stations on eastbound I-70 are located at mileposts 178, 183, 184 (shoulder), 187 (shoulder), 195, 203 (scenic area), 205, 219, 228, 241 and 251. The ten chain stations on westbound I-70 are located at mileposts 263, 260, 254 (Buffalo Overlook), 228, 223, 221, 219, 213 (brake check area) and 197 (scenic area) and 179.

In addition, CDOT has a few chain stations on the I-70 east corridor at mileposts 289 and 343 eastbound and milepost 358 westbound. There is also a chain station located on northbound I-25 at milepost 157 (near Monument) and southbound at milepost 172 (near Larkspur).

The alternate traction control device known as the AutoSock remains an approved device in Colorado. Commercial vehicles (both single and double axle) exceeding 26,000 Gross Vehicle Weight or vehicles carrying 16 passengers or more will have the option of using AutoSock rather than chains. This traction control device is a fabric that slips over a vehicle's outer driving wheels, providing extra traction on snowy and icy roads. It also can be installed over the tire in less time than traditional chains.

To help keep the highways clear and traffic moving, CDOT will continue its heavy tow program for the fifth year in a row. The program is designed to promptly clear disabled heavy trucks from the highway in order to open the road more quickly.

Heavy tow coverage will begin around Thanksgiving and will continue each weekend through late March or early April 2012. Typical hours of operation are Saturdays from 6 a.m. to 2 p.m. on westbound I-70 and Sundays from 2 p.m. to 10 p.m. on eastbound I-70. Other coverage days include Martin Luther King Jr. Day and President's Day. Other days may be added for inclement weather if CDOT deems it necessary.

CDOT also offers the chain assistance program, which allows vendors to assist commercial vehicles when the Colorado Chain Law is in effect by selling and installing chains and other approved equipment. Vendors will be on site at chain stations where the chain law is currently in effect. The service will be available starting around Thanksgiving, depending on weather.

For more information: www.cotrip.org

The Colorado Motor Carriers Association offers these chain-up tips from the state DOT on its website.