Do I need chains?

Yes, CO chain law in effect.
Truck and 53 foot with 5 axle total?

 

No. You would only need chains if you were to be going west on I-70 from Denver.

ww.coloradowdot.info/library/Brochures/ChainTips.pdf

 

Maybe .... U better check the CO DOT website

 

No chains needed. You are only required to carry chains from just west of Denver to MM 133 on I-70.

 

Yep. That's why there's at least two chain-up areas on US287 in Colorado. Your current weather looks OK for the trip, but don't be fooled. You aren't required to carry chains over that route, but the weather will turn nasty quickly. When the chain law goes up over those stretches you will be required to chain, and CDOT is limiting time spent waiting out a storm in the rest areas and chain areas to 24 hours before they start issuing tickets this year.

Just so you know... chains get real expensive later on in the winter. If you don't have 'em and are ordered out of a rest area, you will pay a premium to have someone bring them out to you.

 

The only required carry chain states (for the entire state) is WA and OR between Oct 15 and Apr 30. Other states have carry laws in certain areas such as Donner Pass or Siskiyou Pass in CA IF the signs are up.
CO requires chains between west Denver and Dotsero (mile posts 133 thru 259). There are other places in the Rockies, but I don't travel them, so I don't know.

 

Colorado requires you to carry chains between the I70 mile posts indicated above, Sept. 1st through May 31st every year.

http://www.coloradodot.info/library/Brochures/ChainTips.pdf

However, in the major winter storms we get both in the mountains and on the plains, you can be caught in situations where it is not safe to get from the mess at where you're at to the nearest safe haven without chaining. Any winter storm on the plains has the potential to become a life-threatening blizzard. You are best served to have enough to meet the minimum Colorado chain requirement for travel anywhere in the state.