Traffic Rules
Guam drives on the right, just like the U.S. mainland, so driving here feels familiar. A few local rules still catch visitors off guard: when you may turn right on red, school buses, the yellow center lane, and a strict cell phone law.
This page sums up the rules to know before you drive in Guam. Each explanation cites the relevant section of the Guam Code Annotated (GCA).
Guam traffic rules at a glance
| Topic | The rule in Guam |
|---|---|
| Side of the road | Drive on the right; the steering wheel is on the left |
| Right turn on red | Allowed only after a full stop, when it is safe (not where a sign prohibits it) |
| Speed limit | 45 mph is the maximum anywhere on the island. Follow lower posted limits |
| School buses | Traffic in both directions must stop while children get on or off |
| Yellow center lane | Not a travel lane (for left turns and similar uses only) |
| Cell phones | Holding or using a phone is illegal, even at a red light (hands-free calls excepted) |
| Child seats | Under 4: child seat. Ages 4–11 and under about 144 cm: booster seat or similar |
| Alcohol in the car | Passengers drinking, or open containers in the car, are also illegal |
| Reporting accidents | Written report to the police within 24 hours if anyone is hurt or damage is $50 or more |
Right turn on red: always come to a full stop first
To turn right on red, stop completely before the stop line, then yield to pedestrians in the crosswalk and to traffic moving on a green light before you turn. Where a “NO TURN ON RED” sign is posted, wait for the green light. If you can’t be sure it is safe, it is fine to keep waiting even if the car behind you honks.
When two vehicles enter an intersection without signals at about the same time, the driver on the left yields to the driver on the right (16 GCA §3325).
Speed: 45 mph is a limit, not a target
Guam law prohibits driving faster than 45 mph anywhere, and also requires a speed that is safe for the road, traffic and road surface (16 GCA §3301). Lower limits are posted near schools and in other areas.
| Posted limit | In km/h |
|---|---|
| 15 mph | about 24 km/h |
| 25 mph | about 40 km/h |
| 35 mph | about 56 km/h |
| 45 mph | about 72 km/h |
School buses: traffic in the opposite lanes stops too
When a school bus stops to let children on or off, you must come to a complete stop, whichever direction you are coming from (16 GCA §3336(c)). Do not move or pass until the children have left the road and are safe. When passing a public bus that is picking up or dropping off passengers on the road, slow down to 10 mph or less (16 GCA §3301(d)).
The center lane: use it only to wait for a left turn
On main roads you will see a lane marked with yellow lines between the two directions of traffic. On three-lane roads, Guam law allows the center lane only for passing where you can see clearly ahead, for preparing to turn left, or where signs show its direction (16 GCA §3314(b)). On wider roads, follow the arrows on the pavement and the signs. As a visitor, the safest way to use it is to move in just before a left turn and wait there for a gap in oncoming traffic. Make U-turns only where signs or signals allow them and you can see clearly.
Cell phones: using one is illegal even if it is in a holder
Guam law bans not only holding a cell phone while driving but also using one (16 GCA §3346). Time spent stopped at a red light or in traffic still counts as driving. The only exceptions are hands-free voice calls over Bluetooth or similar (with an earpiece in one ear only) and emergency calls. Set your navigation before you start, and pull off the road and stop before changing it.
Violations are subject to fines, and if a violation contributes to an accident, your license may be suspended or revoked. Guam law also requires rental car companies to tell every renter about this cell phone law (16 GCA §3346.1(e)).
Seat belts and child seats
Everyone in the car must wear a seat belt, in the front and the back. The right child restraint depends on the child’s age and height (16 GCA Ch.26).
- Under 4: an approved child seat
- Ages 4 to 11 and shorter than 144 cm: a booster seat or a child seat that fits
Please reserve child seats when you book your car.
Alcohol in the car: passengers count too
Besides drunk driving, it is a misdemeanor in Guam for passengers to drink in a moving car, and to drive on public roads with an open container of alcohol in the car (9 GCA §§92112–92114). If you take an opened bottle with you, put it in the trunk, not on a seat or in the glove box.
Accidents: call the police and the rental company, even for a minor bump
If you have an accident, stop at the scene, help anyone who is hurt, and exchange names, contact details and vehicle registration numbers with the other party. By law, accidents that injure anyone or cause visible damage of $50 or more must be reported to the police in writing within 24 hours (16 GCA §3502). Repairs to a rental car often cost more than $50 even for a small scratch, so don’t decide for yourself; call both the police and TAICO Rent-A-Car. If anyone is hurt or there is a fire or other danger, call 911.
Learn more
- Complete guide to driving in Guam: main roads, and driving in the rain and at night
- Guam parking guide: which way to park on the street, where parking is prohibited, and tips for hotels and beaches
- Guam traffic violations guide: what to do if police pull you over, and what happens after an accident
This page is based on Guam law (Guam Code Annotated) as of September 2026. Laws can change, and on the road, police instructions, signals, signs and pavement markings always take priority.
