Federal traffic laws and state traffic laws divide the road along a clear line: states run almost everything a typical driver deals with day to day, while the federal government regulates interstate trucking, safety standards for the vehicles themselves, conduct on federal property, and a short list of policy goals it pushes through highway-funding conditions. The agency that writes the rule, the officer who enforces it, and the court that hears your case all depend on which side of that line you land on.
Where the Line Falls
Nearly every ticket a typical driver receives comes from state or local law. Speeding, running a red light, reckless driving, and driving under the influence are state offenses, enforced by state and local police and handled in state court. States get this authority from their general power to protect public health and safety, and they use it to set speed limits, design road markings, define moving violations, and assign license points.
Federal traffic authority is narrower and rests on three constitutional footings: the power to regulate interstate commerce, which covers commercial trucking and vehicle manufacturing; direct control over federal property such as national parks, military bases, and federal buildings; and the spending power, which lets Congress attach strings to the highway money it sends the states. When a federal rule and a state rule cover the same ground and conflict, the federal rule wins. A state cannot permit a trucking practice that federal safety regulations forbid. In most areas of ordinary driving, though, no federal rule exists at all, and state law is the whole story.
Commercial Trucking Is Where Federal Rules Bite Hardest
The Federal Motor Carrier Safety Administration writes and enforces the deepest layer of direct federal traffic regulation under Title 49 of the Code of Federal Regulations. These rules apply to commercial motor vehicles, mostly large trucks and buses running interstate, and they reach nearly every part of a commercial driver’s shift.
Hours Behind the Wheel
A driver hauling property can drive a maximum of 11 hours, and only within a 14-consecutive-hour window that begins after at least 10 consecutive hours off duty. After 8 hours of driving without a break, the driver must take at least a 30-minute interruption before continuing.1eCFR. 49 CFR Part 395 – Hours of Service of Drivers Most commercial drivers must record their duty status on an electronic logging device connected to the engine, rather than on paper.2Federal Motor Carrier Safety Administration. General Information about the ELD Rule
Alcohol, Drugs, and Medical Fitness
Federal impairment rules for commercial drivers are stricter than the state standard that applies to everyone else. A commercial driver cannot report for duty or continue driving with a blood alcohol concentration of 0.04 or higher, half the 0.08 threshold that applies to ordinary drivers under state law.3eCFR. 49 CFR 382.201 – Alcohol Concentration Employers must run drug and alcohol tests before a driver first operates a commercial vehicle, randomly during the year, and after qualifying accidents.4Federal Motor Carrier Safety Administration. When Does Testing Occur and What Tests Are Required Every interstate commercial driver must also carry a current medical certificate from a provider on the FMCSA’s National Registry of Certified Medical Examiners.5National Registry of Certified Medical Examiners. Welcome to the National Registry of Certified Medical Examiners
Licensing and Penalties
Your state DMV issues the commercial driver’s license, but it must follow federal standards for knowledge and skills testing, so a CDL earned in one state means the same thing in every other state.6Federal Motor Carrier Safety Administration. Drivers Repeat convictions for serious violations like excessive speeding, reckless driving, or improper lane changes can disqualify a CDL holder from operating any commercial vehicle for 60 or 120 days depending on the offense count within a three-year window.7eCFR. 49 CFR 383.51 – Disqualification of Drivers Civil penalties reach up to $19,246 per violation for operational infractions by a carrier, up to $15,846 for recordkeeping failures, and up to $4,812 for individual drivers.8Federal Register. Revisions to Civil Penalty Amounts, 2025
Driving on Federal Land
Enter a national park, a military base, or a federal building campus and you are on federal jurisdiction, but the driving rules you follow are often the state rules you already know.
State Rules, Borrowed
National Park Service regulations explicitly adopt the traffic law of the surrounding state as the default. Unless a specific federal regulation says otherwise, state rules govern speed limits, right-of-way, and everyday driving inside the park, and breaking a state traffic law inside the park boundary is itself a federal regulatory violation.9eCFR. 36 CFR 4.2 – State Law Applicable The Assimilative Crimes Act works the same way across other federal property: if no federal statute covers the specific offense, the state’s law fills the gap, carrying the same offense and punishment range that state court would apply.10Office of the Law Revision Counsel. 18 USC 13 – Assimilative Crimes Act The practical result is that speed limits, reckless-driving definitions, and impaired-driving thresholds inside a federal facility usually mirror the rules on the state road just outside the gate.
What Happens to the Ticket
Federal officers do the enforcement: U.S. Park Police in many national parks, military police on installations, Federal Protective Service officers at federal buildings. Their citations run through the Central Violations Bureau, a national center that handles petty offense violations on federal property, including national parks, military installations, post offices, and VA medical centers.11Central Violations Bureau. Frequently Asked Questions
The ticket shows whether you can simply pay the fine or must appear in federal court. Box B lets you pay the collateral amount online or by mail. Box A means an appearance before a federal magistrate judge. Ignoring the citation is risky: the U.S. District Court can issue a summons or an arrest warrant, unpaid fines accrue delinquency fees, and unpaid balances can be sent to the U.S. Treasury for collection.12Central Violations Bureau. Online Payment for Federal Tickets Payment or conviction on a motor vehicle violation may be reported to your home state’s DMV, which can then add points or take other action under its own rules.11Central Violations Bureau. Frequently Asked Questions Serious offenses on federal land, such as reckless driving, can be charged as a Class B misdemeanor carrying up to six months’ imprisonment.13Office of the Law Revision Counsel. 18 USC 3559 – Sentencing Classification of Offenses
The Car You Drive Was Shaped by Federal Rules
Even a driver who never touches a federal road or drives a truck is affected by federal law through the vehicle itself. The National Highway Traffic Safety Administration sets Federal Motor Vehicle Safety Standards that every manufacturer must meet before selling a car, truck, or motorcycle in the United States, covering airbag performance, seat belts, electronic stability control, and crash-test thresholds.14National Highway Traffic Safety Administration. Laws and Regulations
NHTSA also runs the national recall system. When a defect is identified, the manufacturer must notify owners and fix the problem at no charge. Companies that fail to report known defects face civil penalties of up to $27,874 per violation, with a related series of violations reaching roughly $139.4 million.8Federal Register. Revisions to Civil Penalty Amounts, 2025
These same standards control which vehicles can enter the country. A foreign-market vehicle less than 25 years old cannot be permanently imported unless it was originally built to meet all applicable safety standards or NHTSA determines it eligible.15National Highway Traffic Safety Administration. Importation and Certification FAQs Past the 25-year threshold, the exemption kicks in, which is why classic foreign cars appear on American roads at very specific model-year intervals.16U.S. Customs and Border Protection. Importing a Motor Vehicle
How Federal Money Shapes State Traffic Law
Some of the most consequential federal traffic policies were never enacted as direct mandates. Congress told states: adopt this rule, or lose a percentage of your federal highway funding. Because that funding covers a large share of highway construction and maintenance, few states can afford to refuse.
The clearest example is the National Minimum Drinking Age Act of 1984, which required states to prohibit the purchase and public possession of alcohol by anyone under 21. Refusing states originally faced withholding of 10 percent of federal highway apportionments; beginning in fiscal year 2012, that penalty dropped to 8 percent.17Office of the Law Revision Counsel. 23 USC 158 – National Minimum Drinking Age Every state eventually complied, though the federal government never technically banned underage drinking itself.
Congress used the same tool to push states to 0.08 as the per se blood alcohol threshold for impaired driving. Under 23 U.S.C. § 163, states that did not adopt 0.08 faced escalating withholding of certain highway construction funds, capping at 8 percent from fiscal year 2007 onward and dropping to 6 percent starting in fiscal year 2012.18Office of the Law Revision Counsel. 23 USC 163 – Safety Incentives to Prevent Operation of Motor Vehicles by Intoxicated Persons The technique sidesteps the constitutional question of whether Congress could set state DUI thresholds directly. It doesn’t have to.
A Ticket in One State Can Follow You Home
Under 49 U.S.C. § 30304, every participating state’s chief driver licensing official must report to the National Driver Register when a license is revoked, suspended, canceled, or denied for cause, and when a driver is convicted of impaired driving, a fatal-accident violation, reckless driving, racing, or a hit-and-run. Reports are due within 31 days of the state receiving the information.19National Highway Traffic Safety Administration. National Driver Register All 50 states participate.20National Highway Traffic Safety Administration. National Driver Register Frequently Asked Questions
Before issuing or renewing a license, a state must check the NDR for any record on the applicant. That stops a driver whose license was revoked in one state from applying fresh across the border. Most states also participate in the Driver License Compact, a voluntary interstate agreement that reaches further: when you get a ticket in another state, that state notifies your home state, which can apply its own point penalties as if the violation had happened locally. Ignore the out-of-state ticket, and the issuing state can report the failure to appear, letting your home state suspend your driving privileges in response.
REAL ID and the License in Your Wallet
The REAL ID Act set minimum security standards for state-issued identification, and federal enforcement began on May 7, 2025. Since that date, a REAL ID-compliant license or another acceptable form of identification, such as a passport, is required to board domestic flights and enter certain federal facilities. Travelers without compliant identification face a $45 fee at TSA checkpoints.21Transportation Security Administration. REAL ID States still issue and design the licenses themselves; the federal government sets the floor on documentation and security features. That pattern, Washington setting the floor while states run the day-to-day, describes most of where federal traffic authority meets a driver’s life.