Guam-Specific Traffic Laws and Local Road Conditions
Driving on the Island
Guam's roads combine U.S. mainland conventions with tropical and local conditions. Traffic keeps right, signs and signals follow U.S. standards, and the legal drinking age is 21 with a 0.08% BAC limit for adults and zero tolerance for drivers under 21. Seat belts are mandatory, and child restraints are required for young children.
Local conditions shape safe driving here. Heavy rain creates flooding and hydroplaning risk on low-lying roads, and standing water can hide washed-out pavement. Typhoons and tropical storms bring debris, downed power lines, and signal outages - treat dark signals as four-way stops and never drive through flooded roadways. Coral and limestone roads can be slick when wet. Wildlife and free-roaming animals (including carabao and dogs) may appear on rural roads, especially at dawn and dusk. Narrow coastal and village roads demand lower speeds and patience.
Military and federal installations on island may have their own speed limits, ID requirements, and enforcement. School zones and village centers require reduced speed and extra caution for pedestrians.
Traps to Watch
Questions test whether you may drive through floodwater (no - turn around), how to treat an intersection with a dead signal (four-way stop), and whether local roads are safe at the posted limit in rain (no - the basic speed law applies). Watch for questions about animals on the road and about zero-tolerance rules for under-21 drivers.
Rule of Thumb
In the tropics, slow down before the water, not in it - and if you can't see the road's bottom, don't drive through.