State comparison · Updated October 2026
Colorado vs. Utah Driving Laws (2026)
Colorado and Utah differ on 6 of 9 topics we track: max speed limit, phone law, car insurance, car sales tax, new resident deadline and helmet law.
A drive from Denver to Salt Lake City crosses the border, and 6 of the nine laws change on the way. Main routes are I-25 on the Colorado side and I-15 on the side of Utah; the capitals, Denver and Salt Lake City, set the laws for each side.
What changes most: required liability limits differ: 25/50/15 versus 30/65/25. Drivers based in Colorado Springs who drive to West Valley City, and back, live under both sets of rules: Colorado's on I-70 and Utah's once they cross on I-80. Use the Colorado vs Utah guide before driving from Denver to Salt Lake City.
On a weekend drive from Denver to Salt Lake City, pack a helmet and proof of insurance, set navigation before leaving, and expect the limit to change from 75 to 80 mph at the border.
| Topic | Colorado | Utah |
|---|---|---|
| Max speed limit | 75 mph | 80 mph |
| Phone law | Hands-free law | Texting ban only |
| Learner's permit age | Permit at 15 | Permit at 15 |
| Car insurance | 25/50/15 | 30/65/25 |
| Car sales tax | 2.9% | 4.85% |
| Car inspection | Emissions only | Emissions only |
| New resident deadline | 30 days | Right away |
| Helmet law | Under 18 | Under 21 |
| Lane splitting | Filtering only | Filtering only |
Driving laws compared: Colorado vs Utah
Colorado vs Utah: Utah and Colorado agree on learner's permit age: Permit at 15.
Max speed limit: Colorado vs Utah
Utah is faster on max speed limit, with Colorado with 75 mph and Utah at 80 mph. Open-road interstates reach 75 mph in Colorado and 75 mph in Utah. Driving out of Denver for Salt Lake City, verify the posted limit after the border.
Phone law: Colorado vs Utah
Colorado is stricter on phone law, with Colorado with hands-free law and Utah at texting ban only. What you can do with a phone around Denver might not be in Salt Lake City on the other side.
Owning a car compared: Colorado vs Utah
Colorado vs Utah: Utah and Colorado agree on Emissions only for car inspection.
Minimum car insurance requirements: Colorado vs Utah
The rule is higher in Utah on car insurance: Colorado at 25/50/15 and Utah with 30/65/25. Colorado is at-fault while Utah is no-fault. An insurance policy from Denver has to be updated if you relocate to Salt Lake City.
Car sales tax: Colorado vs Utah
Colorado is lower on car sales tax: Colorado at 2.9% and Utah at 4.85%. For a $30,000 purchase, state tax is about $870 in Colorado and $1,455 in Utah. Shoppers in Colorado Springs and West Valley City pay the tax where the car is registered, not the dealer's.
Moving deadlines: Colorado vs Utah
Utah is shorter on new resident deadline, with Colorado at 30 days and Utah at right away. Families moving from Colorado Springs to West Valley City should book DMV appointments early.
Motorcycle: Colorado vs Utah
Colorado vs Utah: Utah and Colorado agree on lane splitting: Filtering only.
Helmet law: Colorado vs Utah
Colorado is looser on helmet law: Colorado at under 18 and Utah with under 21. Riders heading from Denver into Salt Lake City must follow Utah's helmet law on arrival.
Crossing the line for good
- Colorado vs Utah: moving from Colorado to Utah means 60 days to register the car and right away, as soon as you become a resident for the license switch.
- Going from Utah to Colorado: 90 days for registration and 30 days to switch licenses.
Colorado vs Utah: common questions
Where can you drive faster, Colorado or Utah?
Utah (80 mph vs. 75 mph).
Is it cheaper to buy a car — Colorado or Utah?
Colorado charges less at the state level (2.9% vs. 4.85%).
Is a motorcycle helmet mandatory in both Colorado and Utah?
Colorado: Under 18; Utah: Under 21.