Utah's driving laws are mostly what you'd expect, with a few that catch newcomers. The DUI limit is 0.05, the lowest in the country, and under-21 drivers can't have any alcohol. If you're in the left lane and someone comes up behind you, you're required to move right. Express lanes are free with two people. U-turns on the freeway are illegal. School zones are 20 mph.
Every rule here comes from the Utah Driver License Division's 2026 driver handbook and the Utah Highway Safety Office, read Nov. 9, 2026. The handbook is a guide, not the law itself; for the exact wording, see the Utah Code.
The rules, at a glance
| Rule | What Utah says |
|---|---|
| Alcohol limit | 0.05 for drivers 21+; 0.04 commercial; no alcohol under 21 |
| Left lane | Move right when someone approaches from behind |
| Express lanes | Free with 2+ people; otherwise a paid pass |
| Freeway U-turns | Illegal |
| Exiting by an on-ramp | Illegal, even in a jam |
| Right on red | Allowed after a full stop unless posted |
| Left on red | One-way onto one-way only |
| Flashing yellow arrow | Turn after yielding to oncoming traffic and pedestrians |
| Signal | At least 2 seconds before turning or changing lanes |
| School zones | 20 mph when children are present or lights flash |
| Unposted residential or business streets | 25 mph |
| Car seats | Age 8 and under unless 57 inches tall |
The 0.05 limit
Utah lowered its limit from 0.08 to 0.05 on Dec. 30, 2018, and the Highway Safety Office says it's still the only state with a 0.05 limit for drivers 21 and older. Commercial drivers face 0.04, and drivers under 21 fall under a not-a-drop rule.
Officers can also arrest based on observed impairment, whatever the number. The Highway Safety Office lists a first DUI as a Class B misdemeanor with at least 48 hours in jail (or community service or home confinement), fines that typically start around $700 and often pass $1,300 with fees, a license suspension (often 120 days), and possibly an ignition interlock. Refusing a chemical test brings its own immediate suspension. Our DUI and the .05 limit guide goes further.
Freeways: the left lane, express lanes and ramps
- Left lane: a vehicle in the left lane must move safely to the right when approached from behind. On multi-lane roads, the left lane is for passing, and you should never pass on the shoulder.
- Express lanes: free for two or more people. Drivers alone need a paid express pass. Don't cross the double white line except at access points, though you may make a right-hand lane change out of the express lane when it's safe.
- No U-turns on the freeway, and no exiting by an on-ramp, even in a traffic jam.
- Ramp meters: a "meter on" sign means the ramp is metering, and the light may let one vehicle per green.
- Single-point urban interchanges: a U-turn from the off-ramp is allowed only on a green arrow.
Our I-15 Utah County guide covers the express lanes and interchanges here.
Intersections
- Right on red: allowed after a complete stop, unless a sign says no.
- Left on red: only from a one-way street onto another one-way street.
- Flashing yellow arrow: you may turn, but yield to oncoming traffic and pedestrians first.
- Roundabouts flow counterclockwise: slow down, yield to traffic and pedestrians, then signal your exit.
- Signal at least two seconds before turning or changing lanes.
Speed, school zones and school buses
Utah's basic speed law says you may never drive faster than is reasonably safe. Where no sign is posted, the limit is 25 mph in business and residential areas, and 20 mph in school zones while children are going to or leaving school or when the lights are flashing. Stop for a school bus with flashing red lights, and don't go until they stop flashing. Slow down when approaching any stopped emergency vehicle with flashing lights.
Kids in the car
Children 8 and under must ride in an approved car seat unless they're 57 inches tall, and kids should ride rear-facing until at least age 2 and 30 pounds if the seat allows.
Next steps for new residents
Once you're a Utah resident, you'll need a Utah license and registration: see our guides to driver licenses and vehicle registration and emissions. Winter brings its own rules in the canyons; see traction laws and chains.
Related guides
- Moving to Provo
- DUI and Utah's .05 limit
- I-15 in Utah County
- Utah driver license renewal
- Teen driving in Utah
- Winter traction laws and chains
Frequently Asked Questions
What is the legal alcohol limit for driving in Utah?
Do you have to move out of the left lane in Utah?
Can I drive alone in Utah's express lanes?
Can you turn right on red in Utah?
What does a flashing yellow arrow mean in Utah?
Can you make a U-turn on a Utah freeway?
What is the speed limit in a Utah school zone?
How long do I have to signal before turning in Utah?
At what age do kids need a car seat in Utah?
Sources
The facts in this guide were checked against these sources. Hours, fees and rules change, so confirm anything time-sensitive with the source before you go. How we make Provo.com.
- Utah Driver Handbook (Rev. 3.2026), Utah Driver License Division. Checked November 9, 2026.
- Utah Highway Safety Office: 0.05 BAC Law, Utah Highway Safety Office. Checked November 9, 2026.
- Summary of Utah's DUI Laws, Utah Highway Safety Office. Checked November 9, 2026.
