The rules for driving in the United States come down to a short list that every state enforces in some form: carry a valid license, register and insure your vehicle, keep its safety equipment working, obey signs, signals, and speed limits, yield when the law says to yield, stay unimpaired, buckle up, put the phone down, and stop and exchange information if you crash. The details vary by state, but the framework is consistent, and most tickets and civil liability trace back to one of these categories.
License, Registration, and Insurance
You need a license issued by your state’s motor vehicle agency before you drive on public roads. Most states issue a learner’s permit around age 15 or 16, then a full license at 18 after supervised driving hours and a road test. The process generally includes a vision screening (most states require at least 20/40), a written exam on traffic signs and laws, and a behind-the-wheel test. License fees run roughly $25 to $120 depending on the state and class.
Carry the license every time you drive. Most states require you to report an address change within 10 to 30 days so the agency can reach you for legal notices, and medical conditions that affect consciousness or motor control generally must be disclosed. Driving without a valid license can bring a citation or, in some jurisdictions, a misdemeanor charge.
Your vehicle has to be registered with the state, with plates displayed that tie the car to you. Registration renewal is annual or biennial in most states, and standard passenger vehicle fees typically run from about $25 to over $125.
Nearly every state also requires liability insurance before you drive. The most common minimum is 25/50/25: $25,000 for bodily injury per person, $50,000 per accident, and $25,000 for property damage. Some states set property damage minimums as low as $10,000 or $15,000; a few require higher bodily injury limits. Driving uninsured can bring fines, license suspension, vehicle impoundment, or all three.
Vehicle Equipment That Must Work
Safety equipment has to meet minimums at all times, not just at inspection. Headlamps need to work and stay clear of obstructions. Brake lights and turn signals must function and be visible from a reasonable distance to the rear. Tires must keep a minimum tread depth of 2/32 of an inch, which is the depth at which the molded tread wear indicators sit flush with the surface.1National Highway Traffic Safety Administration. Interpretations – 11497AWKM At that point, wet-weather traction drops off sharply. Rearview mirrors must give a clear view of the road behind the vehicle. Equipment violations usually come back as a fix-it ticket requiring repair and proof of compliance within a set deadline.
Signals, Signs, and Right-of-Way
A steady red light means stop completely behind the line. A steady yellow means the signal is about to turn red, so prepare to stop rather than accelerate through. A flashing red works like a stop sign: full stop, then proceed when safe. A flashing yellow means slow down and proceed with caution.
At a four-way stop, the first driver to arrive goes first. When two vehicles arrive at the same moment, the driver on the left yields to the driver on the right. At uncontrolled intersections with no signs or signals, slow down and yield to any vehicle already there or approaching from your right.
Signal before you turn or change lanes. Most states require activating the turn signal at least 100 feet before a surface-street turn, and some require earlier signaling on highways. Keep a safe following distance using the three-second rule: pick a fixed point ahead, and when the vehicle in front passes it, you should be able to count three full seconds before you reach the same point. That gap needs to grow in rain, fog, or heavy traffic.
Roundabouts
Traffic already inside a roundabout has the right-of-way. Slow to roughly 15 mph as you approach, look left for oncoming traffic, and wait for a gap. Once inside, don’t stop and don’t pass other vehicles. Use your right turn signal as you approach your exit. In multi-lane roundabouts, follow posted signs and pavement markings to pick the correct lane before you enter.
Speed Limits and the Basic Speed Law
Posted speed limits set the legal maximum under good conditions. Under the Basic Speed Law, recognized in most states, you must never drive faster than is reasonable for current conditions, which means 55 mph in a 65 mph zone can still get you cited if heavy rain or fog makes that speed unsafe. The posted number is a ceiling, not a guarantee.
Lane discipline matters too. Slower traffic stays right; left lanes are for passing. Sitting in the left lane while traffic stacks up behind you is a ticketable offense in many states. Once you finish a pass, move back to the right.
Sharing the Road
Pedestrians
Yield to pedestrians in crosswalks, marked or not. An unmarked crosswalk exists at virtually every intersection where sidewalks or paths meet the road, even without paint. Stop well back from the crosswalk so drivers in adjacent lanes can see the pedestrian too. Never pass a vehicle stopped at a crosswalk, because someone may be crossing where you can’t see them.2National Highway Traffic Safety Administration. Everyone Is a Pedestrian
Cyclists
At least 35 states and the District of Columbia require motorists to leave a minimum of three feet of clearance when passing a bicyclist, and several more require a “safe distance” without a specific number.3National Conference of State Legislatures. Safely Passing Bicyclists Chart If the lane is too narrow to give that space, wait for oncoming traffic to clear and move partially into the adjacent lane to pass. Cyclists have the same right to use the road as motor vehicles and, in most states, are subject to the same traffic laws.
School Zones
School zones impose reduced speed limits, typically 15 to 25 mph, during the periods when students arrive and leave. These lower limits generally apply about 30 minutes before and after school hours, and the zone is usually marked by signs showing the restricted speed and active times, often with flashing beacons. Fines for speeding in a school zone are significantly higher than standard speeding penalties in most jurisdictions.
Emergency Vehicles and Move Over Laws
All 50 states have Move Over laws. When you see a stopped emergency vehicle with flashing lights, change into a lane that isn’t immediately adjacent to it. If a lane change isn’t safe because of traffic, slow to a reasonable and prudent speed as you pass.4National Highway Traffic Safety Administration. Move Over – It’s the Law Many states extend the same protection to tow trucks, highway maintenance crews, and disabled vehicles with hazard lights on.
When an emergency vehicle approaches from behind with lights and sirens, pull to the right side of the road and stop until it passes. If you’re already in a roundabout, continue to the nearest exit first and pull over past the splitter island.
Seatbelts, Child Restraints, and Phones
Every state except New Hampshire requires adult front-seat occupants to wear a seatbelt. In primary-enforcement states, an officer can pull you over solely for an unbuckled belt. In secondary-enforcement states, the citation can only be added to a stop for a different violation. Fines generally run from $25 to $150.
Children ride in age-appropriate seats. Current guidance is to keep children rear-facing for as long as the car seat allows by height and weight, with a minimum of age two in many states.5National Highway Traffic Safety Administration. Car Seat Recommendations for Children Forward-facing harness seats come after the child outgrows the rear-facing limits, and booster seats are typically required until about age eight or 4 feet 9 inches, depending on the state. The booster can come out once a child fits properly in an adult seatbelt with the back against the seat and knees bending naturally at the seat edge.6National Highway Traffic Safety Administration. Car Seats and Booster Seats
As of 2025, at least 31 states, the District of Columbia, and several U.S. territories enforce a primary ban on handheld cell phone use for all drivers.7Traffic Safety Marketing. Distracted Driving Laws by State Texting while driving is banned for all drivers in nearly every state. Hands-free operation, meaning voice-activated calls or one-touch interfaces, is generally allowed. Fines vary, and the insurance premium increase that follows a citation often costs more than the ticket.
About 21 states have laws specifically prohibiting leaving a child unattended in a vehicle, and prosecutors in other states can still bring charges under general child endangerment laws. Roughly 32 states address animals left in parked vehicles, and about 14 of those allow bystanders to break into a locked car to rescue a distressed animal if they’ve called 911 first and tried less destructive options. Penalties range from fines of a few hundred dollars to misdemeanor criminal charges with potential jail time.
Impaired Driving
Alcohol
Every state, the District of Columbia, and Puerto Rico set the legal blood alcohol concentration limit at 0.08% for adult drivers of non-commercial vehicles.8National Highway Traffic Safety Administration. Lower BAC Limits For drivers under 21, zero-tolerance laws drop that threshold to 0.02% or lower, and some states set it at 0.01%, so essentially any detectable alcohol triggers a violation.9National Highway Traffic Safety Administration. Zero-Tolerance Law Enforcement Commercial drivers face a 0.04% limit in all states.
All 50 states have implied consent laws. By driving on public roads, you’ve already agreed to submit to a breath, blood, or urine test if an officer has reasonable grounds to suspect impairment.10National Highway Traffic Safety Administration. Traffic Safety Facts – Implied Consent Laws Refusing doesn’t help. A first refusal in most states triggers an automatic one-year license suspension, and that suspension applies whether or not you were actually over the limit.11National Highway Traffic Safety Administration. BAC Test Refusal Penalties The administrative suspension runs independently from any criminal DUI charges, so you can end up fighting on two fronts.
You don’t even have to be driving to be charged. Most states recognize “actual physical control” as enough: sitting intoxicated in the driver’s seat with the keys accessible can be sufficient. First-offense DUI penalties commonly include short jail sentences, fines in the hundreds to low thousands, license suspension, and mandatory alcohol education programs.
Marijuana and Other Drugs
Driving under the influence of marijuana or other controlled substances is illegal in every state, but enforcement differs sharply from alcohol. There is no universally agreed-upon impairment threshold for THC comparable to 0.08% for alcohol. Six states have set per se limits for THC in the blood, ranging from 1 to 5 nanograms per milliliter. Eleven states take a zero-tolerance approach, making it illegal to drive with any detectable amount of THC or its metabolites. The rest rely on impairment-based standards, where an officer or Drug Recognition Expert must demonstrate through observation and testing that the drug actually affected your ability to drive.12National Highway Traffic Safety Administration. Drug-Impaired-Driving Laws
There’s a practical complication. THC can remain detectable in blood for days after the impairing effects have worn off. In zero-tolerance states, a positive blood test alone can sustain a charge even if you last used cannabis two days earlier.
After a Crash
Every state requires you to stop if you’re involved in a collision. Pull over as close to the scene as safely possible, check for injuries and call 911 if anyone is hurt, exchange your name, address, license number, and insurance information with the other driver, and cooperate with responding officers. If you hit a parked car or fixed object and can’t find the owner, leave a written note with your contact and insurance information in a visible spot.
Leaving the scene turns an accident into a hit-and-run. With only property damage, that’s typically a misdemeanor carrying fines and possible jail time. When someone is injured or killed, the charge escalates to a felony in most states, with penalties that can include years in prison and a lengthy license revocation.
Most states also require you to file an accident report with your DMV or state police if the crash involved injury, death, or property damage above a set threshold, commonly $1,000 to $2,500. Deadlines run from 24 hours to about 10 days, depending on the state. If a police officer responds and files a report, that usually satisfies the requirement. Failing to file when required can lead to license suspension. Your insurance policy has its own reporting deadline, often 24 to 72 hours, and missing it can give the insurer grounds to dispute your claim.