Irish Drivers in the US 2026: Keep Right, State Rules, 0.08%
Ireland
United States
Each US state sets its own rule on visitor licences; the 1949 IDP is the treaty document both countries recognise. The big change is driving on the right, with limits in mph and a 0.08% alcohol line.
The licence card changes least on an Irish driver’s trip to the States. The side of the road changes most, and the rulebook changes every time you cross a state line.
Licence and permit
The United States has no single national rule on foreign licences; each state decides how long a visitor may drive on one, and rental companies add their own conditions. What ties the two countries together is the 1949 Geneva Convention on Road Traffic, which Ireland joined in 1962 and the United States in 1950. Under it, a 1949 international driving permit is the document American authorities are bound to recognise. An Irish licence is printed in English, which helps at a roadside stop, but the IDP is cheap and removes doubt. Carry the licence, permit and passport together; the Driving Permit Checker helps for multi-state trips.
Driving on the right
Ireland keeps left; America keeps right. The risk is highest in ordinary moments: pulling out of a car park, turning across traffic, a reflex glance over the wrong shoulder. Sit on the left of the car, stay to the right of the road and resist drifting back to the kerb side after each turn. Start on quiet streets, not downtown.
Speeds and alcohol
Limits are posted in miles per hour and set by each state and road, so an interstate can be faster in one state than the next. Ticket amounts are set locally and vary widely; the Speeding Fine Calculator gives a rough idea. The WHO profile lists the US blood-alcohol limit at 0.08%. Ireland’s general limit is 50 mg per 100 ml, and 20 mg for learner, novice and professional drivers. A US drink-driving arrest carries jail risk and licence loss, so keep to zero.
Call 911 for police, fire and ambulance anywhere in the country. The US driving guide covers state differences.
Sources
- UN Treaty Collection, 1949 Convention on Road Traffic (United States 1950, Ireland 1962): treaties.un.org
- WHO Global status report on road safety 2023, United States profile (0.08 g/dl): who.int
- Irish Statute Book, Road Traffic Act 2010, section 4 (50 mg general; 20 mg for learner, novice and professional drivers): irishstatutebook.ie
- GOV.UK foreign travel advice, USA getting help (911 for police, fire and ambulance): gov.uk
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Frequently Asked Questions
There is no single federal rule: each state decides how long a visitor may drive on a foreign licence. Ireland and the United States are both parties to the 1949 Geneva Convention, so a 1949 international driving permit is the document American authorities are bound to recognise. It is inexpensive insurance against a state or rental desk that asks for one.
Switching to the right-hand side of the road. Ireland drives on the left, so junctions, turns and overtaking all run in reverse. Take your first drive somewhere quiet.
Yes. The WHO profile lists 0.08% for the United States; Ireland's general limit is 50 mg per 100 ml (0.05%), and 20 mg for learner, novice and professional drivers. A US arrest for drink-driving brings jail risk and licence loss, so do not use the margin.