Like others have said, depends on the time of day, but compared to other cities, Denver's traffic isn't that bad. With that said, I store my RV South of Denver, and the maintenance is done at a shop North of Denver. I have an account setup (you can too, it's easy, but if this is a one time trip for you, may not be worth it).
www.expresstoll.com/ You basically fill out an online form, and they send you the stickers to put in your windshield. Your credit card is automatically deducted. However, if you wish not to setup an account, they will send you a bill in the mail, at a higher rate, based on your license plate (picture taken as you go through).
From my latest Express Toll bill, and I'm not towing.
From I25 South (Toll Plaza A) to I25 North (Toll Plaza E).
https://www.expresstoll.com/Document...bsite-2015.pdf
3/23/2017 2:27:25 PM E470 PLAZA E Lane 2 South AVITOLL $2.95
3/23/2017 2:36:24 PM E470 PLAZA D Lane 2 South AVITOLL $5.90
3/23/2017 2:42:55 PM E470 PLAZA C Lane 2 South AVITOLL $5.90
3/23/2017 2:49:43 PM E470 PLAZA B Lane 2 South AVITOLL $5.90
3/23/2017 3:01:53 PM E470 PLAZA A Lane 2 South AVITOLL $5.40
Total: $26.05
Sorry, this may be more information than you really wanted.

My wife prefers this route, as we've seen downtown Denver enough, that we like to avoid it when possible.
Hope this helps you or someone else.
Cheers