United StatesUnited States
Traffic rules
United States
1. United States
The United States spans most of North America between Canada and Mexico, with additional states in Alaska and the Pacific. Traffic drives on the right. The Interstate Highway System links major cities and regions across enormous distances, while driving conditions range from dense urban freeways to deserts, mountain passes and sparsely populated rural highways. Winter snow and ice can be severe in northern and mountainous regions, while other areas face hazards such as extreme heat, heavy rain or hurricanes. Distances are shown in miles and speed limits in miles per hour (mph), rather than kilometres.
Most everyday traffic rules are established by the individual states and local authorities, so speed limits, child-restraint laws, motorcycle helmet requirements and mobile-phone restrictions can differ considerably. There is no nationwide vignette; most roads are free, while individual toll roads, bridges and express lanes use operator-specific payment systems. Traffic signs broadly follow the federal MUTCD standard and written signs are predominantly in English.
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Which side of the road do you drive on in the United States?
Drive on the right-hand side of the road.
Which side should you overtake on in the United States?
Normally overtake on the left. Passing on the right is permitted in certain situations under state law, particularly on multi-lane roads.
What is the emergency telephone number in the United States?
Call 911 for police, fire or emergency medical assistance.
Are traffic rules the same throughout the United States?
No. Most everyday road rules are established by individual states and sometimes local authorities. Speed limits, mobile-phone restrictions, child-restraint requirements, motorcycle helmet laws and other rules can therefore differ from one state to another.
What is the alcohol limit for drivers in the United States?
For drivers aged 21 or older, the per-se BAC limit is 0.08% in every state except Utah, where it is 0.05%. A driver can still be prosecuted for impairment at a lower BAC where the circumstances support it.
What is the alcohol limit for drivers under 21 in the United States?
All states have zero-tolerance laws for drivers under 21. These laws use very low permitted alcohol concentrations, generally below 0.02%, with the exact threshold depending on the state.
What is the alcohol limit for commercial drivers in the United States?
Federal rules use a BAC threshold of 0.04% for drivers operating commercial motor vehicles that require a commercial driver's licence.
What are the general speed limits in the United States?
There is no nationwide urban, rural or motorway speed limit. Each state establishes statutory and posted limits, and cities or other authorities may set additional local limits. Always follow the posted speed-limit signs.
What is the speed limit on Interstate highways in the United States?
There is no single Interstate speed limit. Limits vary by state, road section and sometimes vehicle type, and higher-speed rural highways can have substantially different limits from urban Interstate sections.
What is the highest posted speed limit in the United States?
A section of Texas State Highway 130 is posted at 85 mph, approximately 137 km/h. This is exceptional and should not be treated as a general U.S. motorway limit.
Do school zones have the same speed limit throughout the United States?
No. School-zone limits and the times when they apply are determined by state or local rules. Follow the signs and flashing signals at each school zone.
Do you need a vignette to drive in the United States?
No. There is no nationwide road vignette. Most roads are free to use, while tolls apply to particular highways, bridges, tunnels and express lanes.
How are road tolls paid in the United States?
Payment depends on the toll operator. Many facilities use electronic toll collection or number-plate billing. Systems include E-ZPass and I-PASS in many eastern and Midwestern states, FasTrak in California, and other regional systems elsewhere.
Are seat belts compulsory in the United States?
Seat-belt laws are established by the states. Every state except New Hampshire has an adult seat-belt law, although the occupants covered and whether police can stop a vehicle solely for a seat-belt violation vary by state.
Does New Hampshire require adults to wear seat belts?
New Hampshire is the national exception: it currently has no general seat-belt law for adult occupants. Its restraint requirements still apply to younger passengers. Wearing a seat belt remains strongly recommended regardless of the legal exception.
Are child car seats compulsory in the United States?
Yes. States have child-passenger restraint laws, but the required ages, heights, weights and types of restraint vary. Check the law of the state in which you are driving rather than assuming one national age or height threshold.
Are motorcycle helmets compulsory in the United States?
There is no nationwide helmet-use rule. Some states require helmets for every rider and passenger, others require them only for younger or specified riders, and some do not impose a general motorcycle helmet requirement on adults. Where a compliant helmet is required, state laws commonly refer to the federal DOT safety standard.
Can you use a mobile phone while driving in the United States?
Mobile-phone laws are state-specific. Many states prohibit handheld phone use, texting or both, and learner or young drivers often face stricter restrictions. Check the applicable state law and avoid handling a phone while driving.
Who has priority at an uncontrolled intersection in the United States?
Rules are established by the states, but a common rule is that when two vehicles reach an otherwise equal uncontrolled intersection at approximately the same time, the driver on the left yields to the vehicle on the right. Signs and other priority rules take precedence.
Who has priority at a roundabout in the United States?
Drivers entering a modern roundabout should yield to traffic already circulating inside it and obey the applicable Yield signs, lane markings and pedestrian crossings.
Can you turn right at a red light in the United States?
In most jurisdictions, a right turn on red is allowed after a complete stop if the way is clear and no sign prohibits it. Important local exceptions exist: in New York City, turning on red is generally prohibited unless a sign specifically permits it.
Do pedestrians have priority at crosswalks in the United States?
Pedestrian right-of-way rules are set by state and local law. Drivers must yield or stop for pedestrians at crosswalks where the applicable law requires it and should watch carefully for both marked and legally recognised unmarked crossings.
What should you do when a school bus has flashing red lights in the United States?
In every state, you must not pass a stopped school bus from behind while its red lights are flashing and stop arm is extended. Rules for traffic approaching from the opposite direction vary on divided and multi-lane roads, so check the state's school-bus law.
What is the Move Over law in the United States?
All 50 states have Move Over laws. When approaching a stopped emergency vehicle displaying flashing lights, move into a non-adjacent lane when it is safe to do so or slow down as required. Some states extend the rule to maintenance, utility or disabled vehicles.
Should slower traffic keep right in the United States?
State laws differ in detail, but drivers should generally keep right except when overtaking or when another manoeuvre requires a different lane, particularly on higher-speed multi-lane highways. Obey Keep Right and lane-use signs.
Can tourists drive in the United States with a foreign driving licence?
Usually, but the requirements are determined by the state in which you are driving. Visitors should carry their valid foreign licence and check each state's motor-vehicle authority for its recognition and time-limit rules.
Do tourists need an International Driving Permit in the United States?
Not in every state. Some states require or recommend an International Driving Permit in addition to the original foreign licence. An IDP must be obtained before travelling; the United States does not issue one to foreign visitors after arrival.
Are winter tyres or snow chains compulsory in the United States?
There is no nationwide winter-tyre or snow-chain rule. States can impose their own traction requirements on particular roads or during winter conditions. Mountain states and regions such as California and Colorado can require suitable tyres, chains or other traction devices when restrictions are active.
What language and measurement units are used on U.S. road signs?
Written road signs are predominantly in English, together with standardized symbols. Road distances are normally shown in miles and speed limits in miles per hour (mph). Bilingual or multilingual signs can appear in some locations.
