Preventative Maintenance Programs for Semi-Truck
April 1, 2026
Every trucker knows the highway can throw you a curveball. From changing weather conditions to traffic jams and sun glare to mechanical issues, you never know what you might face on a long-haul route. It’s essential to recognize that truck maintenance laws vary by state, as do commercial truck inspection requirements, adding further considerations to your plate when facing an extended ride.
Knowing the truck maintenance laws by state and individual commercial truck inspection requirements is just as important as keeping your rig in gear. What might be okay in one state could get you flagged by the highway patrol in another, and if your semi-truck is out of compliance, you can face hefty fines and even an out-of-service (OOS) order. These hiccups can delay your job big time, costing you along the way. Whether you’re driving coast to coast or managing an interstate fleet, understanding how semi-truck maintenance laws vary across the country is crucial to staying legal, safe, and inspection-ready.
How Truck Maintenance Laws Are Regulated in the U.S.
Truck maintenance laws in the U.S. combine federal regulations and state-specific requirements. While the Federal Motor Carrier Safety Administration (FMCSA) sets baseline safety and maintenance standards for all commercial vehicles engaged in interstate commerce, individual states often add layers of rules.
These can vary in areas such as emissions testing, local enforcement authority, and required documentation. Understanding the relationship between federal standards and state-specific regulations is crucial for staying compliant on the road.
What to Expect in Each State’s Maintenance Requirements
Each state maintains authority over specific aspects of truck maintenance and enforcement of inspections. States may differ in how frequently inspections are required, how they enforce lighting and brake standards, and what kind of emissions testing is needed. However, some maintenance expectations remain consistent due to federal regulations. States may not override federal rules, but they can add additional laws that drivers must follow.
Vehicle Inspections: Annual, Safety, and Emissions
Under FMCSA rules, all commercial motor vehicles are required to undergo an annual inspection that covers brakes, steering, suspension, lighting, tires, and other critical components. Some states require additional periodic inspections or emissions tests.
For drivers seeking a reliable place to complete these inspections, select LubeZone locations offer DOT inspection services to help keep your truck compliant year-round. Below, we’ll review commercial truck inspection requirements by state to help you stay in compliance.
Equipment Standards: Brakes, Tires, Lights, and More
Federal law establishes minimum equipment standards that every semi-truck must meet, regardless of its operating location. These include truck brake and tire rules. For example:
- Brake systems must meet FMVSS 121 standards and be inspected regularly.
- Tires must maintain a tread depth of at least 4/32 inch on front wheels and 2/32 inch on other wheels.
- Lighting and reflectors must remain functional and meet placement standards outlined in 49 CFR Part 393.
States can apply stricter standards or require additional safety features, such as tire chains, during winter.
Enforcement: Who Can Stop and Cite You
FMCSA grants inspection authority to state and local law enforcement agencies that participate in the Motor Carrier Safety Assistance Program (MCSAP). Additionally, states may assign roadside enforcement to highway patrol, commercial vehicle enforcement divisions, or local law enforcement agencies. For example:
- California: The California Highway Patrol (CHP) Commercial Division conducts the majority of truck inspections.
- Texas: Department of Public Safety enforces truck laws.
- New York: State Police and DMV Motor Carrier Inspectors share duties.
Being aware of who can stop you helps avoid surprises at weigh stations or roadside inspections.
When Federal Law Overrides State Rules
Federal law takes precedence in interstate commerce. That means FMCSA rules override conflicting state laws for drivers and fleets operating across state lines. For example, if a state has looser brake inspection intervals than FMCSA standards, the federal rule still applies. However, intrastate drivers must follow their state’s specific requirements unless they also engage in interstate travel.
Using This Guide as a Trucking Reference
Many truckers cover multiple states on a single haul. That means knowing each state’s truck maintenance laws helps you avoid costly citations or delays. This guide provides the highlights, enabling you to plan ahead and stay inspection-ready, regardless of your travel destination.
Before entering a new state, it’s a smart move to:
- Review the state’s Department of Transportation (DOT) website for the latest updates.
- Confirm emissions and safety inspection requirements.
- Understand the local roadside enforcement authority.
State-by-State Truck Maintenance Law Summaries
Each state summary below provides a brief overview of the required inspections, equipment regulations, emissions standards, and roadside enforcement procedures. Use this section to spot what’s different and what to look out for as you cross state lines.
Staying aware of changing laws and regulations is an essential responsibility when operating a semi-truck. It helps ensure legal compliance, avoiding costly downtime and administrative hassle. Remember, if any questions arise, it’s always best to check with each state’s governing body regarding specific legislation.
Alabama
Required Vehicle Inspections
Alabama follows the FMCSA’s requirement for annual DOT inspections for all interstate commercial vehicles. Intrastate carriers must also comply with the state’s Commercial Vehicle Safety Alliance (CVSA) inspection procedures.
Additionally, drivers must complete a driver/vehicle inspection report and submit it to the Motor Carrier Safety Unit within 15 days of an inspection.
Equipment Standards
Alabama aligns with federal requirements on brakes, tires, and lighting. Brake components must pass minimum wear thresholds, and lighting must remain functional at all times. Tread depth standards follow the federal minimum.
Emissions or Environmental Testing
Alabama does not require emissions testing for heavy-duty diesel trucks statewide.
Roadside Enforcement Authority
The Alabama Law Enforcement Agency (ALEA) handles commercial vehicle inspections and enforces maintenance regulations at weigh stations and random stops.
Additional Notes or State Resources
Trucking companies must maintain detailed records of all maintenance and inspection events. For more details, please visit the Alabama Department of Transportation – Motor Carrier Services website.
Alaska
Required Vehicle Inspections
Alaska requires all commercial vehicles over 10,000 pounds to undergo annual inspections in line with FMCSA standards. Intrastate operations must also maintain documentation proving compliance with state and federal inspection rules.
Additionally, any commercial vehicle with a gross vehicle weight rating (GVWR) of 10,001 pounds or more must stop at any open weigh station or roadside inspection site.
Equipment Standards
Brake systems, tire tread depth, lighting, and reflectors must comply with federal minimums. In Alaska’s winter conditions, chains may be required in certain regions during periods of icy conditions. Always follow local ordinances and pay attention to weather alerts.
Emissions or Environmental Testing
Emissions regulations in Alaska restrict visible exhaust plumes from both gasoline and diesel-powered vehicles, as per the requirements of 18 AAC 52.015(a).
Roadside Enforcement Authority
The Alaska Department of Public Safety and local law enforcement divisions oversee roadside enforcement. Commercial Vehicle Enforcement Officers regularly perform inspections at weigh stations and checkpoints.
Additional Notes or State Resources
One important thing to note about trucking in Alaska is that commercial truck drivers are subject to extended hours of service regulations, which permit longer driving and duty times compared to the rest of the United States. In Alaska, truckers have a 20-hour duty-time window, as opposed to the standard fourteen. Drivers in the Lower 48 have an 11-hour window for driving. However, Alaskan drivers have 15 hours while within state lines.
Visit the Alaska Department of Transportation & Public Facilities for updates on regional and seasonal truck requirements.
Arizona
Required Vehicle Inspections
Arizona follows FMCSA regulations, which require annual DOT inspections for commercial vehicles operating across state lines. Intrastate carriers must also comply with Arizona Department of Transportation (ADOT) inspection policies, which mirror federal standards for most equipment categories.
Equipment Standards
Arizona enforces federal brake, tire, and lighting standards. Trucks must meet minimum requirements for tread depth, braking efficiency, and visibility. Reflective tape and lighting are closely monitored, especially on trailers and during night operations.
Emissions or Environmental Testing
The Phoenix and Tucson metro areas require diesel emissions testing for heavy-duty vehicles over 8,500 pounds. Vehicles operating within these regions must pass periodic opacity and exhaust control inspections under the Vehicle Emissions Inspection Program (VEIP), overseen by the Arizona Department of Environmental Quality.
Roadside Enforcement Authority
The ADOT Enforcement and Compliance Division, in cooperation with the Arizona Department of Public Safety (DPS), performs roadside inspections and enforces vehicle safety standards at checkpoints and weigh stations.
Additional Notes or State Resources
Visit the Arizona Department of Transportation – Enforcement and Compliance page for more details on inspection scheduling and requirements, or refer to Title 28 from the Arizona State Legislature, which outlines transportation compliance.
Arkansas
Required Vehicle Inspections
Arkansas requires annual DOT inspections for all commercial motor vehicles in interstate operation, consistent with FMCSA regulations. Intrastate carriers must maintain inspection records to ensure they meet commercial truck inspection requirements and follow similar standards.
Equipment Standards
The state adheres to federal requirements for brakes, tires, lights, and mirrors. Brake systems must be in good working order and properly adjusted. Tread depth must meet or exceed federal minimums. Lighting and reflector systems must function correctly and meet placement guidelines.
Emissions or Environmental Testing
Arkansas does not currently require emissions testing for semi-trucks statewide. However, operators must comply with federal anti-idling guidelines and EPA emissions regulations for diesel engines.
Roadside Enforcement Authority
The Arkansas Highway Police, a division of the Arkansas Department of Transportation (ARDOT), conducts vehicle inspections and enforces regulations governing commercial vehicles. Officers conduct roadside inspections at weigh stations and through mobile patrols.
Additional Notes or State Resources
For current laws and enforcement updates, visit the Arkansas Department of Transportation’s Commercial Vehicle Enforcement website.
California
Required Vehicle Inspections
California requires annual DOT inspections for all interstate commercial vehicles based on FMCSA standards. Additionally, the California Highway Patrol (CHP) conducts random roadside inspections at weigh stations and enforcement checkpoints. Intrastate-only vehicles must keep current inspection certificates on board.
Equipment Standards
The state enforces federal requirements for brake systems, tire tread, lighting, and reflectors. Truckers should regularly monitor brake lining thickness and ensure that trailer lights, clearance lights, and reflective tape meet the standards outlined in 49 CFR Part 393. California also enforces special requirements, such as the mandatory use of wheel covers to reduce tire debris on highways.
Emissions or Environmental Testing
California enforces rigorous emissions standards under the California Air Resources Board (CARB). Most heavy-duty diesel trucks must comply with CARB’s smoke opacity and particulate matter inspections. Vehicles often need to meet CARB’s diesel truck emission control laws and may require periodic smoke testing at authorized locations.
Roadside Enforcement Authority
CHP’s Commercial Vehicle Section enforces maintenance and safety standards at highway checkpoints, ports, and rural enforcement areas. CHP officers can conduct full Level I inspections and issue out-of-service orders for safety violations.
Additional Notes or State Resources
For detailed regulations and service guidelines, refer to the California Highway Patrol Commercial Vehicle Enforcement and the CARB Heavy-duty Diesel Rule.
Colorado
Required Vehicle Inspections
Colorado requires annual DOT inspections for all commercial motor vehicles, with proof carried in the vehicle and copies in the maintenance files, as per 49 CFR 396.17.
Equipment Standards
Colorado enforces both federal requirements and state-specific vehicle markings, which include the company name, DOT number, and the last eight digits of the vehicle identification number (VIN) on the passenger side. Necessary emergency equipment consists of a fire extinguisher (5 B:C rating) and reflective triangles.
Additionally, Colorado law requires truckers to carry chains from September 1 to May 31 when traveling on I-70 between Morrison and Dotsero.
Emissions or Environmental Testing
Colorado requires emissions testing for gasoline-powered vehicles in the Metro Denver and Front Range region, including portions of Adams, Arapahoe, Boulder, Broomfield, Denver, Douglas, Jefferson, Larimer, and Weld counties.
Heavy-duty trucks from model year 2008 and newer must undergo Onboard Diagnostic (OBD) tests starting in March 2025, replacing the Two-Speed Idle (TSI) test for more accurate nitrogen oxide emissions evaluation. The opacity standard for diesel vehicles has been lowered from 40% to 20% opacity, measured over five seconds.
Roadside Enforcement Authority
Colorado State Patrol’s Motor Carrier Safety Section conducts roadside inspections and enforcement to reduce commercial vehicle-related crashes and hazardous materials incidents.
Officers can conduct comprehensive inspections, issue citations, and place vehicles out of service for safety violations.
Additional Notes or State Resources
For detailed regulations and compliance information, refer to the Colorado State Patrol Motor Carrier Safety Section and the Colorado Department of Transportation Commercial Vehicle Information.
Connecticut
Required Vehicle Inspections
Connecticut state law requires annual federal inspections, as specified in 49 CFR 396.17, for commercial vehicles exceeding 18,000 pounds in use for intrastate commerce (or 10,000 pounds in interstate commerce). Roadside inspection violations must be corrected and reported within 15 days per state MCSAP requirements.
Equipment Standards
Connecticut enforces Federal Motor Carrier Safety Regulations, including service brakes, steering components, lighting, and DOT number display requirements.
Emissions or Environmental Testing
Connecticut follows federal EPA emissions standards without additional state-specific commercial vehicle emissions testing programs.
Roadside Enforcement Authority
Connecticut DMV truck squads patrol highways and six weigh stations. P.O.S.T. certified inspectors conduct Level 1 inspections with arrest authority.
Additional Notes or State Resources
Visit Connecticut DMV Commercial Safety. Update DOT numbers within two years and provide insurance and drug testing program information to state authorities.
Required Vehicle Inspections
Delaware requires inspections for all vehicles being titled for the first time, performed at no fee at four DMV facilities. Inspections may occur 90 days before registration expiration.
Equipment Standards
Delaware inspects lights, brakes, glass, tires (2/32″ tread depth minimum), and mufflers. Commercial vehicles must meet federal lighting and equipment requirements.
Emissions or Environmental Testing
Delaware conducts emissions testing for vehicles with a gross vehicle weight rating (GVWR) of up to 14,000 pounds, excluding pre-1997 diesel vehicles. The state DMV mandates both idle emissions testing and an Onboard Diagnostic (OBD II) Test.
Roadside Enforcement Authority
The Delaware State Police and DOT officers conduct roadside inspections and enforce commercial vehicle safety regulations throughout the state.
Additional Notes or State Resources
Visit Delaware DMV Vehicle Services and Delaware DOT Commercial Portal for inspection information and commercial vehicle requirements.
Florida
Required Vehicle Inspections
Florida requires annual DOT inspections for all commercial vehicles engaged in interstate commerce. Intrastate carriers must also comply with Florida Highway Patrol (FHP) inspection rules. Records of inspections must be retained and made available during roadside checks.
Equipment Standards
Florida follows FMCSA standards for brake systems, lighting, tire tread depth, and other safety equipment. Semi-trucks must ensure that lighting is fully operational, brakes are within wear limits, and tires meet or exceed the federal minimum tread depth requirements.
Emissions or Environmental Testing
Florida does not require emissions testing for heavy-duty diesel trucks statewide. However, some counties have local air quality monitoring and may impose temporary restrictions during pollution alerts.
Roadside Enforcement Authority
The FHP Commercial Vehicle Enforcement division conducts truck inspections and roadside enforcement throughout the state, including at weigh stations and during random highway stops.
Additional Notes or State Resources
Special notes regarding Florida and truck maintenance laws by state include the state’s specific guidelines surrounding weight and size limits, intrastate operating hours, and the transportation of hazardous materials. The state has specific guidelines regarding size and weight that vary depending on the type of roadway, the type of vehicle, and the cargo being transported. Additionally, Florida’s hours-of-service rules state that drivers operating only within the state may have different maximum driving times and rest periods compared to interstate drivers.
Refer to the Florida Department of Highway Safety and Motor Vehicles’ Commercial Vehicles section for official regulations and updates.
Georgia
Required Vehicle Inspections
Georgia requires all interstate commercial motor vehicles to comply with FMCSA’s annual inspection standards. Intrastate operators must also maintain inspection records and follow Georgia-specific commercial vehicle rules.
Equipment Standards
Georgia enforces all federally mandated standards for brake, tire, and lighting equipment. Brake systems must pass performance checks, tires must have legal tread depth, and all lights must remain visible and functional.
Emissions or Environmental Testing
Heavy-duty diesel trucks are not required to undergo emissions testing in Georgia; however, environmental restrictions may apply in the metro Atlanta area and surrounding counties.
Roadside Enforcement Authority
The Georgia Department of Public Safety (DPS) Motor Carrier Compliance Division (MCCD) conducts roadside inspections and enforces safety and maintenance standards. Rules and regulations are overseen by the Georgia Department of Transportation.
Additional Notes or State Resources
Georgia semi-truck maintenance laws regulate speed, weight (e.g., the maximum gross weight for a truck in Georgia is 80,000 pounds), height, width, and length limits per vehicle. They also cover requirements regarding CDL acquisition, load securement, fleet management, and insurance coverage.
Visit the Georgia Department of Public Safety – MCCD for more information.
Hawaii
Required Vehicle Inspections
Hawaii mandates a safety inspection for all commercial vehicles every 12 months, including semi-trucks. Trucks must display a valid inspection decal to operate legally on public roads, letting officials know they meet state commercial truck inspection requirements. Additionally, all motor carriers must maintain a Vehicle Maintenance File for each commercial motor vehicle in their operation.
Equipment Standards
Semi-trucks in Hawaii must meet federal equipment standards. Brake condition, lighting systems, and tire tread are all subject to visual and performance inspection during the annual check. Drivers must report any defects or deficiencies that impact the vehicle’s safety or cause a breakdown, and carriers must rectify such issues before re-dispatching the vehicle.
Emissions or Environmental Testing
Hawaii does not require emissions testing for diesel semi-trucks, but it may impose environmental standards for vehicles operating in environmentally sensitive zones.
Roadside Enforcement Authority
The Hawaii Department of Transportation (HDOT) and local law enforcement agencies share responsibility for roadside enforcement, particularly around ports and highways.
Additional Notes or State Resources
Details are available at the Hawaii Department of Transportation – Motor Vehicle Safety Office.
Idaho
Required Vehicle Inspections
Idaho follows FMCSA rules for annual DOT inspections on commercial vehicles over 10,000 pounds. Specialized permits (e.g., for oversized loads) also require inspections under 49 CFR 396.17. Inspectors must be certified per federal standards. Drivers must keep inspection reports on board and update them whenever repairs are completed.
Equipment Standards
Idaho enforces federal minimum standards for brakes, tires, lighting, and coupling devices, and has specific state legislation regarding semi-truck tires. Inspectors at Ports of Entry and roadside checkpoints assess brakes, tires, exhaust systems, and turn signals under CVSA standards.
Tires with built-in studs may be used when required for safety due to snow, ice, or other conditions that cause vehicles to skid. However, studs are not allowed between May 1 and September 30 each year.
Emissions or Environmental Testing
Idaho does not currently require emissions testing for semi-trucks statewide.
Roadside Enforcement Authority
The Idaho State Police Commercial Vehicle Safety Division and Port of Entry inspectors conduct Level I inspections and can issue out-of-service orders under CVSA criteria.
Additional Notes or State Resources
For rules and inspector contact information, visit the Idaho State Police Commercial Vehicle Safety Division.
Illinois
Required Vehicle Inspections
Illinois requires regular safety inspections for commercial vehicles on the following schedule: Intrastate carriers must be examined every six months, and interstate carriers must undergo annual inspections. Documentation for a prior inspection must be kept onboard the vehicle for 14 months.
Equipment Standards
Illinois enforces federal standards for truck brake and tire rules, lighting, and reflector specifications. Violations during safety audits or compliance reviews by IDOT and ISP can result in citations.
Emissions or Environmental Testing
Illinois requires emissions testing for semi-trucks, as per the Illinois Environmental Protection Agency (IEPA). Intrastate diesel-powered vehicles that fall under this policy include:
- Trucks registered for a gross weight of more than 16,000 pounds, and:
- Registered within the affected area, and:
- Two years or older model year.
Emissions are tested annually, with a focus on vehicles operating within ozone non-attainment areas in Illinois.
Roadside Enforcement Authority
The Illinois State Police Commercial Vehicle Enforcement Division conducts roadside inspections and compliance reviews in partnership with IDOT’s Vehicle Compliance Program.
Additional Notes or State Resources
Visit the IDOT Vehicle Compliance Programs page or Illinois ISP for inspection schedules and guidelines.
Indiana
Required Vehicle Inspections
Indiana requires annual DOT inspections for all commercial motor vehicles, consistent with FMCSA and adopted for intrastate carriers. Vehicles must display a valid inspection sticker or documentation on board.
Equipment Standards
Indiana enforces federal requirements on brakes, tires, lighting, steering, suspension, and coupling. Compliance reviews can uncover worn brakes—a leading cause of truck crashes in Indiana.
Emissions or Environmental Testing
Indiana does not generally require emissions testing for heavy-duty trucks, though federal EPA anti-idling and emissions rules still apply. Additionally, heavy-duty diesel-powered vehicles with a GVWR of 8,500 pounds or less may be subject to emissions testing in Lake and Porter Counties.
Roadside Enforcement Authority
Indiana State Police Commercial Vehicle Enforcement officers conduct roadside inspections and safety audits, enforcing FMCSR standards, including issuing out-of-service orders.
Additional Notes or State Resources
For more details on inspections and enforcement, visit the Indiana State Police Commercial Vehicle Enforcement page.
Iowa
Required Vehicle Inspections
Iowa requires annual DOT inspections for all commercial vehicles weighing more than 10,000 pounds, following the FMCSA’s 12-month inspection cycle. Inspectors must meet federal qualifications, and the inspection report or sticker stays onboard for 14 months.
Equipment Standards
The state strictly follows FMCSA minimums for brakes, tires, lighting, reflectors, and coupling devices. Inspectors assess safety systems during both full and walk-around inspections.
Emissions or Environmental Testing
Iowa currently does not require emissions checks for heavy-duty diesel trucks.
Roadside Enforcement Authority
The Iowa DOT Motor Vehicle Enforcement Unit and Iowa State Patrol conduct Level I inspections at weigh stations and highway checkpoints.
Additional Notes or State Resources
Additionally, it’s essential to note that out-of-state commercial motor vehicles entering Iowa for maintenance and repair are required to obtain a temporary entry and exit permit. For detailed rules and inspector contacts, visit the Iowa DOT Motor Vehicle Enforcement website.
Kansas
Required Vehicle Inspections
Kansas requires annual DOT inspections for interstate commercial vehicles conducted by qualified inspectors certified under the 49 CFR 396.17 and 396.19 standards. Intrastate carriers also follow those rules. Additionally, the Kansas Highway Patrol requires VIN inspections for vehicles with out-of-state titles.
Equipment Standards
Follows federal standards for brakes, tires, lighting, and load securement. Brake system inspections must meet FMCSA criteria, and inspectors must attest to their qualifications.
Emissions or Environmental Testing
Kansas does not require emissions testing for heavy-duty trucks.
Roadside Enforcement Authority
The Kansas Highway Patrol enforces commercial vehicle safety and can perform roadside checks and compliance inspections.
Additional Notes or State Resources
An important note states that regulated carriers must comply with requirements for biennial medical examinations of their drivers. Visit the Kansas Corporation Commission Transportation Division for inspection guidelines.
Kentucky
Required Vehicle Inspections
Kentucky enforces annual DOT-compliant inspections for interstate trucks and operates intrastate inspections under the same rules. Inspectors may conduct checks anytime and anywhere.
Equipment Standards
The state enforces FMCSA standards for brakes, tires, lighting, steering, and suspension. The Commercial Vehicle Enforcement (CVE) division of the State Police can cite worn brakes during roadside or terminal inspections.
Emissions or Environmental Testing
Kentucky does not mandate diesel emissions checks statewide. Boone, Kenton, Campbell, and Jefferson Counties may have their own regulations regarding emissions.
Roadside Enforcement Authority
The Kentucky State Police Division of Commercial Vehicle Enforcement handles random inspections, enforcement actions, and out-of-service orders.
Additional Notes or State Resources
In Kentucky, trucking companies are required to establish and maintain a policy that covers vehicle maintenance procedures. For more information and contact details, please visit the Kentucky CVE website.
Louisiana
Required Vehicle Inspections
Louisiana allows carriers to use a state-issued Commercial Motor Vehicle Inspection certificate in place of the federal DOT Calendar Annual Inspection. Inspections must cover all major components, and repair findings must be documented in the inspection report.
Equipment Standards
Commercial vehicles must meet federal standards for brakes, tires, lighting, mirrors, and coupling devices. In specific parishes, such as Baton Rouge, trucks must also obtain an annual “brake tag” via an on-road brake test.
It’s essential to note that specific truck components, including emergency door lights, require inspection at least every 90 days.
Emissions or Environmental Testing
Louisiana’s Vehicle I/M program requires emissions safety inspections for vehicles under 10,000 pounds only. Heavy-duty diesel semi-trucks are exempt.
Roadside Enforcement Authority
The Louisiana State Police Transportation and Safety Services division enforces maintenance and safety regulations. Inspectors can issue out-of-service orders during roadside checks or weigh station inspections.
Additional Notes or State Resources
The MGVM in Louisiana is 80,000 pounds, but vehicles with tridem or greater axle groups can exceed this limit, up to 83,400-88,000 pounds. No single axle can exceed 30,000 pounds.
For forms and detailed requirements, see the Louisiana Department of Transportation & Development’s “Regulations for Trucks, Vehicles & Loads” manual.
Maine
Required Vehicle Inspections
Maine requires annual safety inspections for commercial motor vehicles weighing more than 10,000 pounds, including trailers weighing more than 7,000 pounds, in accordance with FMCSA standards. Inspectors must be certified, and vehicles must display a valid inspection sticker or report during roadside stops.
Equipment Standards
Safety inspections include brakes, lights, tires, steering, suspension, and coupling systems as outlined in North American Standard (CVSA) procedures.
Emissions or Environmental Testing
Maine conducts emissions testing for semi-trucks with a GVWR of over 18,000 pounds. Testing must be completed annually at licensed Diesel Emission Inspection Centers (DEIC) within 90 days of the vehicle’s registration or renewal.
The test involves a “snap-acceleration test” where the engine is rapidly accelerated to maximum speed, measuring smoke opacity at the exhaust pipe. This is part of a regional program that includes many New England states, as well as New York and New Jersey.
Vehicles manufactured before 1990 have a 55% opacity limit, while those manufactured in 1990 or later have a 40% opacity limit.
Roadside Enforcement Authority
The Maine State Police Motor Vehicle Inspection Program conducts roadside safety inspections and reviews inspection compliance at certified stations.
Additional Notes or State Resources
For more information, visit the Maine Department of Transportation website.
Maryland
Required Vehicle Inspections
Maryland requires commercial vehicles to pass both federal-compliant periodic inspections and state-level pre-registration inspections for in-state or incoming out-of-state vehicles. Eligible inspectors include Maryland State Police and other certified personnel.
The state has strict inspection standards, where semi-trucks are subject to Preventive Maintenance Program (PMP) inspections at least every 35,000 miles or annually (whichever comes first). Trucks over five years old must pass inspection every 25,000 miles.
Equipment Standards
The state enforces preventive maintenance programs for truck fleets, requiring annual documented inspections for brakes, lights, tires, and steering components.
Emissions or Environmental Testing
Diesel-powered vehicles with a gross combination or gross vehicle weight rating over 10,000 pounds are subject to emissions testing in the state of Maryland. The test measures the opacity of exhaust emissions and is administered by the state’s Diesel Vehicle Emissions Control Program.
Roadside Enforcement Authority
Commercial Vehicle Safety Units within the Maryland State Police and the Maryland Transportation Authority Police conduct roadside inspections and can issue out-of-service orders on major highways.
Additional Notes or State Resources
Refer to the Maryland Motor Carrier Handbook and COMAR Ch. 11.22.02 for preventive maintenance regulations.
Massachusetts
Required Vehicle Inspections
Massachusetts requires annual DOT inspections for all semi-trucks over 10,000 lbs in interstate operation, per FMCSA guidelines. Commercial vehicles must display a valid inspection decal or carry a certificate during roadside checks.
It’s also important to note that commercial truck drivers in Massachusetts require special CDLs, with requirements based on the type and weight of the vehicles they operate.
Equipment Standards
The state enforces federal standards on brakes, tires, lighting, mirrors, steering, and coupling devices. Inspectors follow North American Standard (CVSA) procedures for safety audits.
Additionally, as of February 2025, the Massachusetts Department of Transportation (MassDOT) has finalized a unique set of semi-truck safety equipment requirements. These requirements mandate lateral protective devices, convex mirrors, crossover mirrors, and backup cameras on trailers and semi-trailers classified as Class 3 or above, with a gross vehicle weight rating of 10,001 lbs+, that are leased or purchased by the Commonwealth on or after Jan. 1, 2023, or operated under a contract with the Commonwealth on or after Jan. 1, 2025.
Emissions or Environmental Testing
Massachusetts requires semi-trucks to pass annual emissions tests at a certified state inspection station. Vehicles with onboard diagnostic systems (OBDII) are tested for emissions, while older or non-OBDII vehicles are subject to opacity (smoke) tests.
Roadside Enforcement Authority
The Massachusetts State Police Commercial Vehicle Unit (commonly referred to as “the truck team”) and MassDOT Highway Division perform inspections at weigh stations and during highway patrol stops.
Additional Notes or State Resources
The Massachusetts Commercial Motor Vehicle Inspection is considered equivalent to the annual FMCSA inspection; therefore, if drivers have a Massachusetts state inspection, a separate DOT inspection is typically not necessary.
Visit the Massachusetts RMV website for commercial vehicles to access regulatory updates and inspection guidelines.
Michigan
Required Vehicle Inspections
Michigan mandates annual FMCSA-compliant DOT inspections for all interstate commercial motor vehicles, including semi-trucks. Intrastate vehicles must also complete similar commercial truck inspection requirements and carry current documentation. Additionally, motor carriers in Michigan must keep written maintenance schedules for their vehicles.
Equipment Standards
The state enforces federal equipment standards for brakes, tires, lights, steering, suspension, and securement. Inspectors also monitor the placement and securing of reflectors during roadside checks.
Emissions or Environmental Testing
Emissions testing for heavy-duty diesel trucks is not required statewide, although localized anti-idling zones may impose restrictions.
Roadside Enforcement Authority
Michigan State Police Commercial Vehicle Enforcement and Michigan Department of Transportation officers conduct Level I and II inspections at ports of entry and highway enforcement stops.
Additional Notes or State Resources
Visit Michigan MDOT Commercial Vehicles for inspection station listings and compliance resources.
Minnesota
Required Vehicle Inspections
Minnesota requires annual DOT-style inspections for all semi-trucks operating on interstate highways. Intrastate carriers are required to maintain inspection records in the cab and adhere to North American Standard inspection protocols.
Equipment Standards
Minnesota enforces FMCSA standards for brakes, tires, lighting, mirrors, steering, and HAZMAT securement (if applicable). Inspectors ensure reflective tape and safety devices comply with 49 CFR Part 393.
Emissions or Environmental Testing
Minnesota does not require emissions testing for all vehicles; however, semi-trucks with a gross vehicle weight rating (GVWR) of 14,000 pounds or less may be subject to annual emissions testing. Heavy-duty diesel trucks in the Twin Cities metro area may also be subject to emissions testing as part of the region’s air quality management efforts.
Roadside Enforcement Authority
The Minnesota State Patrol’s Commercial Vehicle Section and Department of Public Safety conduct roadside safety inspections and compliance reviews at both stationary and mobile checkpoints.
Additional Notes or State Resources
For complete regulations and inspection checklists, visit the Minnesota Department of Public Safety – CVIU.
Mississippi
Required Vehicle Inspections
Mississippi requires annual DOT inspections for interstate semi-trucks following FMCSA guidelines. Intrastate carriers must also maintain current inspection records onboard. Inspectors verifying compliance can conduct full North American Standard inspections at weigh stations.
Equipment Standards
The state applies federal standards for brakes, tire tread depth, lighting, reflectors, steering, and coupling devices. Inspectors will cite worn brake pads or damaged lights during roadside checks and safety audits. Additionally, semi-trucks weighing over 10 tons must have mud flaps in Mississippi.
Emissions or Environmental Testing
Mississippi does not enforce emissions testing for heavy-duty diesel trucks. However, operators must comply with federal anti-idling and emissions regulations. Semi-trucks with a GVWR of 26,001 pounds+ are subject to exhaust emission opacity standards, for which tests may be conducted at any certified inspection and weigh station.
Roadside Enforcement Authority
The Mississippi Highway Safety Patrol’s Commercial Vehicle Enforcement Division conducts roadside inspections and compliance checks and issues out-of-service orders by FMCSA and CVSA standards.
Additional Notes or State Resources
Visit the Mississippi Department of Transportation or Highway Safety Patrol for up-to-date inspection guidelines and safety bulletins.
Missouri
Required Vehicle Inspections
Missouri requires annual DOT inspections for all semi-trucks operating on the interstate in accordance with FMCSA rules. Intrastate fleets must maintain inspection certificates and records in the cab for verification during stops.
Equipment Standards
The state enforces federal requirements for brakes, tires, lights, reflectors, suspension, and couplings. State auditors may also review securement practices and mirror visibility. Additionally, drivers must complete a written report at the end of each driving day if they discover any defects during the trip.
Emissions or Environmental Testing
Missouri requires that semi-trucks with a GVWR of 18,000 lbs+ pass annual emissions testing for smoke emissions at a licensed DEIC within 90 days of registration and renewal. All diesel vehicles manufactured after 1997, regardless of weight, must also pass emissions testing in the GVIP program area (including the city of St. Louis, Jefferson, St. Charles, and St. Louis counties).
Roadside Enforcement Authority
The Missouri State Highway Patrol Commercial Vehicle Unit and Missouri Department of Transportation conduct roadside inspections and can place vehicles out of service for violations.
Additional Notes or State Resources
For forms and state-specific updates, check the Missouri Department of Transportation – Commercial Vehicles page.
Montana
Required Vehicle Inspections
Montana follows FMCSA’s annual inspection requirement for interstate trucks. Intrastate commercial carriers must document inspections and keep them onboard for official review.
Equipment Standards
Federal standards for brakes, tires, lighting, and coupling are enforced. Montana mandates that commercial trucks carry tire chains between October 1st and May 31st.
Emissions or Environmental Testing
Montana does not currently require emissions testing for semi-trucks; however, drivers in areas such as Missoula and Butte should be aware of local air quality advisories.
Roadside Enforcement Authority
The Montana Highway Patrol’s Commercial Vehicle Division inspects trucks during weigh station operations and roving enforcement stops. The DMV may also perform audit inspections at terminals.
Additional Notes or State Resources
Visit the Montana Department of Transportation – Motor Carrier Services for complete inspection and service information.
Nebraska
Required Vehicle Inspections
Nebraska requires commercial vehicles to undergo annual federal DOT inspections, following 49 CFR Part 396 for commercial truck inspection requirements. Trucks must carry inspection documentation in the cab and may be audited during roadside stops or weigh station checks.
Equipment Standards
Vehicles must comply with federal safety standards for brakes, tires, lighting, mirrors, and coupling systems. Nebraska enforces additional visibility and clearance lighting requirements during winter driving months.
Emissions or Environmental Testing
Nebraska does not mandate emissions testing for heavy-duty diesel trucks. However, the state supports voluntary clean diesel initiatives and encourages participation in EPA SmartWay programs.
Roadside Enforcement Authority
The Nebraska State Patrol Carrier Enforcement Division has the authority to stop, inspect, and cite vehicles for maintenance or safety violations. Mobile units conduct random inspections across major trucking corridors.
Additional Notes or State Resources
Additionally, Nebraska participates in the PRISM (Performance Registration Information Systems and Management) program, which links a carrier’s safety record to its ability to register trucks. Visit the Nebraska DMV Carrier Services for forms, manuals, and compliance checklists.
Nevada
Required Vehicle Inspections
Nevada adheres to federal annual inspection rules under 49 CFR 396.17 for commercial truck inspection requirements. Vehicles operating within the state must carry valid documentation and may be subject to Level I or II inspections at Nevada Highway Patrol checkpoints.
Equipment Standards
Trucks must meet federal requirements for brakes, tires, steering, lighting, and other safety systems. Nevada also requires fire extinguishers and emergency reflective triangles in all commercial cabs. In Nevada, trucks are subject to weight limits based on their axle count.
Emissions or Environmental Testing
Diesel emissions testing is required in Clark and Washoe counties for trucks registered at 14,000 pounds or more. Testing frequency depends on the vehicle’s age and registration type. Heavy-duty trucks are generally exempt from emissions and environmental testing in the state of Nevada.
Roadside Enforcement Authority
The Nevada Highway Patrol Commercial Enforcement Unit performs safety inspections at fixed and mobile sites. They may issue citations or out-of-service orders for noncompliant vehicles.
Additional Notes or State Resources
Check the Nevada DMV Emissions Program for updated county testing rules.
New Hampshire
Required Vehicle Inspections
New Hampshire mandates annual safety inspections for commercial trucks over 10,000 lbs. These must comply with federal FMCSA regulations and be performed at licensed state inspection facilities.
Equipment Standards
Federal standards apply statewide, including brake performance, tire tread depth, lighting, and suspension system requirements. Inspectors also review the condition of reflective tape and underride guards.
Emissions or Environmental Testing
In New Hampshire, trucks weighing 14,001 pounds or more are exempt from annual emissions inspections. However, they must comply with opacity standards for visible smoke. Diesel-powered vehicles under 14,000 pounds GVWR from model year 1968 and newer are required to have an annual emissions test, as per the state DMV.
Roadside Enforcement Authority
The New Hampshire State Police Troop G Commercial Enforcement Unit has the authority to stop, inspect, and issue citations for vehicle violations. Level I and II inspections are common along I-93 and I-89 corridors.
Additional Notes or State Resources
Refer to the New Hampshire Department of Safety – Road Toll Bureau for information on fuel permits and motor carrier regulations.
New Jersey
Required Vehicle Inspections
New Jersey requires an annual DOT-style inspection for all heavy-duty commercial vehicles (18,000 lb GVWR+) conducted at a licensed Private Inspection Facility (PIF) or inspection station. Random roadside checks also occur.
Equipment Standards
The state enforces federal standards for truck brakes and tire rules, as well as lighting, mirrors, and securement. Inspectors also verify glazing standards (windshield and window certification) in accordance with the New Jersey Administrative Code.
Emissions or Environmental Testing
Diesel trucks over 18,000 lb GVWR must pass annual emissions inspections within 90 days of registration or renewal. Random roadside opacity checks can also trigger citations. Find a diesel emissions testing site here.
Additionally, NJ also has the Advanced Clean Trucks (ACT) rule, which aims to accelerate the transition to zero-emission vehicles. It requires manufacturers to sell a certain percentage of zero-emission trucks each year. Sales percentages are set to increase from 2025 through 2035.
Roadside Enforcement Authority
MVC inspectors and NJ State Police collaborate on roadside inspections using snap‑acceleration tests. Out-of-service orders may be issued for safety or emissions violations.
Additional Notes or State Resources
Visit NJ MVC’s Commercial Inspection Info for program details and licensed PIF directories.
New Mexico
Required Vehicle Inspections
New Mexico State Police CVE performs DOT-compliant inspections at Ports of Entry and roadside checkpoints. Intrastate documentation is required under 49 CFR 396 for commercial truck inspection requirements.
Equipment Standards
The state enforces FMCSA standards on braking systems, tires, lighting, coupling devices, and securement. Ports also inspect for overweight permits and proper credentials.
Emissions or Environmental Testing
New Mexico has enacted Advanced Clean Cars and Advanced Clean Trucks rules to reduce emissions from both light and heavy-duty vehicles. Manufacturers must deliver more zero-emission vehicles, including semi-trucks, to the state. However, diesel vehicles are currently exempt from emission testing in the state.
Roadside Enforcement Authority
The New Mexico State Police CVE and MVD’s Commercial Vehicle Bureau conduct safety audits and roadside inspections and enforce OOS orders.
Additional Notes or State Resources
Visit the New Mexico Truckers Guide or NMDOT’s Transportation Regulation Bureau for carrier compliance info.
New York
Required Vehicle Inspections
New York mandates annual heavy-duty commercial DMV inspections, and vehicles must display a valid inspection certificate. FMCSA compliance is required for interstate carriers.
Equipment Standards
Standards for brakes, tires, lighting, glazing, coupling, and suspension follow federal guidelines. Inspectors must meet the qualifications for interstate and in-state trucks.
Emissions or Environmental Testing
New York conducts roadside emissions inspections for all vehicles with an MGW of 8,500 lbs+ if that vehicle is registered in the state. Drivers whose vehicles fail a roadside emissions inspection may receive a fine of $700 for the first offense and $1,300 for any subsequent offense.
Additionally, New York State has adopted the California Advanced Clean Trucks (ACT) regulation for heavy-duty trucks, including semi-trucks. ACT requires manufacturers to sell increasing percentages of zero-emission vehicles (ZEVs) in NY starting in 2025.
Roadside Enforcement Authority
New York State Police and DMV Heavy Vehicle Inspection Program officers perform inspections on major routes and at inspection stations. OOS orders may be issued for serious violations.
Additional Notes or State Resources
Check the NYS DMV commercial inspection guide for locations, vehicle classes, and inspection standards.
North Carolina
Required Vehicle Inspections
North Carolina follows federal DOT guidelines for annual inspections of commercial motor vehicles weighing over 10,000 pounds. Operators must retain documentation and may be subject to audits by state or federal inspectors.
Equipment Standards
Trucks must comply with FMCSA brake, lighting, tire, and safety component rules. The North Carolina Highway Patrol enforces these standards with regular roadside inspections.
Emissions or Environmental Testing
There are no specific diesel emissions test requirements for heavy-duty trucks statewide. However, North Carolina encourages participation in voluntary emissions reduction programs and anti-idling efforts. Additionally, 19 counties do require emissions tests, which include Onboard Diagnostic (OBD) testing for vehicles from 1996 and newer.
Find a list of those counties and more information from the NC Dept. of Environmental Quality.
Roadside Enforcement Authority
The North Carolina State Highway Patrol Motor Carrier Enforcement Section can stop, inspect, and place vehicles out of service for violations. Inspections often occur along major corridors such as I-40 and I-85.
Additional Notes or State Resources
North Carolina requires commercial vehicle owners in the state to carry a minimum of $750,000 in liability insurance. See NC DMV IRP and IFTA Services for vehicle registration and compliance and more.
North Dakota
Required Vehicle Inspections
North Dakota adheres to 49 CFR Part 396 for annual commercial vehicle inspections. Documentation must be maintained and presented upon request during roadside inspections. ND does not require state inspections; however, it does enforce inspections on trucks carrying oil and gas as a precautionary measure against hazards.
Equipment Standards
Federal equipment standards apply across North Dakota, including minimum tire tread depth, lighting requirements, and brake functionality. All trucks must carry emergency equipment. Additionally, vehicles must be equipped with safety glazing material that meets specific standards.
Emissions or Environmental Testing
The state does not require emissions testing for commercial diesel trucks. However, excessive visible emissions may lead to citations under general nuisance or opacity rules.
Roadside Enforcement Authority
The North Dakota Highway Patrol Motor Carrier Operations Division conducts regular roadside checks. Violations may result in citations or out-of-service orders.
Additional Notes or State Resources
Visit ND Highway Patrol Motor Carrier for permit forms and regulations.
Ohio
Required Vehicle Inspections
Ohio requires annual inspections for commercial trucks operating under FMCSA guidelines. Operators must retain inspection documentation and ensure availability for roadside review.
Equipment Standards
The Ohio State Highway Patrol enforces federal equipment standards, including regulations governing truck brakes and tires. Intrastate carriers must also comply with state rules that are consistent with FMCSA standards.
Emissions or Environmental Testing
Ohio does have emissions standards for semi-trucks. These standards involve testing, self-inspection, and compliance with state smoke opacity standards. New regulations for truck model years 2027 and later will mandate even stricter standards. Learn more at the Ohio Public Utilities Commission Motor Carrier Safety Handbook.
Roadside Enforcement Authority
Ohio State Highway Patrol inspectors conduct routine stops on highways and weigh stations. Out-of-service criteria follow FMCSA guidelines.
Additional Notes or State Resources
Review Ohio DPS Commercial Vehicle Enforcement for more on inspections and safety regulations.
Oklahoma
Required Vehicle Inspections
Oklahoma requires annual DOT-style inspections (49 CFR 396) for all CMVs over 10,000 lb. Qualified officers in the Commercial Vehicle Traffic Enforcement Program (CVTEP) and Port-of-Entry inspectors conduct Level I and II inspections on interstate and intrastate trucks.
Equipment Standards
Federal standards apply for brakes, tires, lighting, steering, coupling devices, and securement. CVTEP troopers are cross-trained to inspect HAZMAT and cargo tank trucks when required.
Emissions or Environmental Testing
Oklahoma follows federal emission standards for heavy-duty vehicles, including semi-trucks and other large commercial vehicles. OK does require vehicle emissions inspections, which may include semi-trucks. However, most vehicles with a weight of 10,001 lbs+ are exempt from this testing.
Roadside Enforcement Authority
The Oklahoma Highway Patrol CVTEP and Port-of-Entry inspectors have the authority to stop, inspect, and issue out-of-service (OOS) orders for maintenance violations.
Additional Notes or State Resources
See the Oklahoma DPS Roadside Inspection Program for officer certifications and program details.
Oregon
Required Vehicle Inspections
Oregon conducts annual commercial vehicle inspections consistent with FMCSA standards, including each truck unit in a combination. Trucks with valid inspection decals from another jurisdiction receive reciprocity unless defects are visible. Depending on the truck’s mileage and usage, the state may require more frequent inspections. Learn more at the Oregon Department of Transportation.
Equipment Standards
Oregon enforces federal equipment standards, including brakes, tires, lighting, mirrors, and coupling devices, during both fixed-scale and mobile inspections within CVSA protocols.
Emissions or Environmental Testing
Oregon follows the ACT Rule, like several other states, including New Jersey and California, as well as the Heavy-Duty Engine and Vehicle Omnibus Rule. This rule requires manufacturers to sell lower-emitting truck engines in Oregon, specifically targeting nitrogen oxides. The Omnibus Rule lowers emission standards for conventionally fueled new heavy-duty trucks and went into effect in July 2024.
Oregon DOT’s Commerce and Compliance Division partners with state police to conduct Level I and II inspections at weigh stations and during highway patrol stops.
Additional Notes or State Resources
Inspectors and carriers can access inspection reports and audit details via the Oregon Trucking Online system.
Pennsylvania
Required Vehicle Inspections
Pennsylvania requires annual DOT-style inspections documented on the MV‑431 form and displayed with a yearly certificate. These commercial truck inspection requirements apply to CMVs over 17,000 lb.
Equipment Standards
PennDOT and FMCSA enforce federal standards for brakes, tires, lighting, reflectors, steering, suspension, and coupling—ensuring these are inspected during annual safety checks. View the state’s full vehicle equipment legislation here.
Emissions or Environmental Testing
Pennsylvania automatically incorporates and follows changes to California’s emission standards for heavy-duty diesel engines. This means that PA follows California’s regulations regarding engine and emission system requirements. Learn more at the Pennsylvania Heavy-Duty Emissions Control Program website.
Additionally, the Diesel-Powered Motor Vehicle Idling Act in PA (Act 124 of 2008) limits idling time for diesel vehicles with a gross weight of 10,001 pounds+ to five minutes within any 60 minutes.
Roadside Enforcement Authority
PennDOT safety inspectors, as well as Pennsylvania State Police Commercial Vehicle Enforcement, conduct roadside inspections and safety audits and can issue out-of-service (OOS) orders.
Additional Notes or State Resources
PennDOT’s Safety Inspection Program provides MV-431 forms, certified station directories, and FAQs to facilitate compliance.
Rhode Island
Required Vehicle Inspections
Rhode Island requires annual safety inspections for commercial trucks over 8,500 lb GVWR, including trailers over 1,000 lb. Inspections follow the state’s Official Manual and must be performed at authorized stations.
Equipment Standards
Inspectors check brake systems, tire condition, lighting, mirrors, suspension, and the condition of reflective tape and under-ride guards as part of the annual inspection.
Emissions or Environmental Testing
Rhode Island requires heavy-duty diesel vehicles, including semi-trucks, to undergo periodic emissions inspections. Rhode Island also follows the California ACT legislation. Vehicles with an 8,500 lbs GVWR must pass an emissions test annually, along with a smoke opacity test. Learn more about testing at the RI DMV.
Additionally, RI prohibits any diesel truck from idling for more than five consecutive minutes within one hour.
Roadside Enforcement Authority
The DMV’s licensed inspection stations perform annual inspections. Commercial vehicle enforcement may occur through state police at weigh stations and major border crossings.
Additional Notes or State Resources
Refer to the Rhode Island Inspection Program manual and DMV’s website for inspection station locations and certified inspector qualifications.
South Carolina
Required Vehicle Inspections
South Carolina mandates annual DOT-compliant inspections for all commercial vehicles conducted by qualified inspectors by FMCSA standards and state Appendix G rules.
Equipment Standards
Brakes, tires, lighting, reflectors, steering, and coupling must meet federal criteria. Inspection records must be kept on board and available during roadside audits.
Emissions or Environmental Testing
SC participates in the federal Diesel Emissions Reduction Act (DERA) program and has its regulations regarding vehicle idling and state emissions testing. In SC, trucks with a GVWR of 10,000 lbs+ cannot idle for more than 10 minutes in any one hour.
Additionally, owners of diesel fleets comprising nine or more vehicles in SC that weigh 14,000 pounds or more (empty weight) must self-inspect and certify their vehicles annually to meet state smoke opacity standards. Smaller fleets and owners must conduct this certification at a state site.
Roadside Enforcement Authority
The South Carolina Highway Patrol and SC DOT personnel conduct regular safety inspections at weigh stations and other enforcement sites, using North American Standard protocols.
Additional Notes or State Resources
Review the SC DMV commercial vehicle portal for inspection report requirements and qualified inspector info.
South Dakota
Required Vehicle Inspections
South Dakota requires annual federal-style DOT inspections for all commercial vehicles, following 49 CFR 396 standards. Inspection records should be kept in the cab for compliance purposes.
Equipment Standards
The state enforces federal standards for brakes, tires, lighting, and coupling devices. Inspectors may also enforce emergency safety device requirements.
Emissions or Environmental Testing
South Dakota does not impose any vehicle emissions testing, though the Department of Agriculture offers voluntary clean-diesel programs.
Roadside Enforcement Authority
The South Dakota Highway Patrol and local SD DOT inspectors perform roadside inspections and can issue out-of-service orders under FMCSA criteria.
Additional Notes or State Resources
Visit the South Dakota Air Quality Program and Department of Agriculture for info on voluntary emissions initiatives.
Tennessee
Required Vehicle Inspections
Tennessee requires annual DOT-style inspections for commercial motor vehicles, with certificates carried onboard. Qualified inspectors conduct Level I and II inspections both at fixed sites and roadside checkpoints.
Equipment Standards
Tennessee enforces federal specs on brakes, tires, lighting, steering, suspension, and coupling. Inspectors verify compliance with CVSA standards during audits and roadside inspections.
Emissions or Environmental Testing
There is no statewide emissions test requirement for semi-trucks and vehicles over 10,500 pounds. GVWR is currently exempt from Tennessee’s annual emissions testing program.
Roadside Enforcement Authority
The Tennessee Highway Patrol and Tennessee Department of Safety inspect commercial vehicles on highways and interstates, with the authority to issue out-of-service orders under FMCSA rules.
Additional Notes or State Resources
It’s important to note that TN law restricts the maximum weight of commercial vehicles to 80,000 pounds. Additionally, trucks with a GVWR of 10,001 lbs+ must stop at weigh stations, even when empty.
Further details and contact info are available through the Tennessee Department of Safety Motor Carrier Division.
Texas
Required Vehicle Inspections
Texas requires annual TX DOT inspections for all commercial vehicles over 26,000 lb GVWR. Records of inspection must be available during roadside or weigh station inspections.
Equipment Standards
The Texas Department of Public Safety enforces federal equipment standards for brakes, tires, lighting, wiring, steering, and load securement. Violations such as worn brake linings or broken lights can trigger citations or orders.
Emissions or Environmental Testing
Diesel semi-trucks in certain counties must pass an emissions test if they are between 2 and 24 years old. These counties include Brazoria, Collin, Dallas, Denton, El Paso, Ellis, Fort Bend, Galveston, Harris, Johnson, Kaufman, Montgomery, Parker, Rockwall, Tarrant, Travis, and Williamson counties.
Learn more at the Texas Commission on Environmental Quality.
Roadside Enforcement Authority
The Texas DPS Commercial Vehicle Enforcement Division and DPS Highway Patrol conduct inspections statewide and hold the authority to pull vehicles out of service for safety violations.
Additional Notes or State Resources
Fee schedules, guidelines, and inspection site locations are outlined on the Texas DPS Commercial Vehicle Enforcement page.
Utah
Required Vehicle Inspections
Utah requires annual DOT inspections for commercial vehicles operating on interstate highways. Inspection certificates must be carried in the truck and shown to CmV officers upon request.
Equipment Standards
The state enforces federal standards for brakes, tires, lighting, steering, suspension, and coupling equipment. Reflective devices and lighting systems are subject to strict checks, particularly during winter.
Emissions or Environmental Testing
In Utah, semi-trucks are subject to emissions testing, particularly within specific counties, based on vehicle weight and model year. Emissions checks are required for registration and renewal in areas like Salt Lake, Davis, Utah, Weber, and Cache counties. Larger fleets or vehicles weighing over 14,000 lbs may qualify for self-inspection.
Learn more at Utah.gov.
Roadside Enforcement Authority
The Utah Highway Patrol and Unified Statewide System (UHP and UDOT) Commercial Vehicle Enforcement Division conduct road checks and station inspections and can issue out-of-service orders.
Additional Notes or State Resources
See the Utah UHP Commercial Vehicle Enforcement page for inspection guidelines, locations, and official contacts.
Vermont
Required Vehicle Inspections
Vermont requires commercial vehicles to pass annual safety inspections. The state recognizes FMCSA inspection standards for trucks operating interstate and mandates proof of compliance.
Regardless of weight, all trucks must enter Vermont’s weigh stations and inspection areas when they are open.
Equipment Standards
All commercial vehicles must meet federal brake, lighting, steering, tire, and suspension standards. Vermont inspectors check for compliance at inspection stations and during road stops.
Emissions or Environmental Testing
VT follows California’s ACT laws, like many other states. The state also has warranty requirements for emissions control systems on all vehicles and regulations concerning exhaust smoke. Learn more at the Vermont Department of Environmental Conservation webpage.
These programs are overseen by VT’s Vehicle Emissions Inspection and Maintenance Program, the VT DMV, and the VT Air Quality and Climate Division.
Roadside Enforcement Authority
The Vermont Department of Motor Vehicles Enforcement Division and State Police Commercial Motor Vehicle Inspectors conduct safety inspections and citations.
Additional Notes or State Resources
More information is available via the Vermont DMV Commercial Vehicles website.
Virginia
Required Vehicle Inspections
Virginia mandates annual inspections for all commercial vehicles. Trucks operating interstate must comply with federal DOT inspection rules and carry documentation onboard.
Equipment Standards
The Virginia State Police enforce federal equipment standards for brakes, lighting, tires, and visibility reflectors. Inspectors cite violations during both roadside checks and weigh station stops.
Emissions or Environmental Testing
There is no statewide requirement for diesel emissions testing on semi-trucks. Anti-idling regulations are in effect in select counties, particularly in urban areas. View Virginia’s vehicle emissions regulations on the state legislature’s website.
Roadside Enforcement Authority
The Virginia State Police Motor Carrier Safety Unit performs inspections and enforces FMCSA compliance at weigh stations and road checkpoints.
Additional Notes or State Resources
Additionally, Virginia enforces a maximum gross vehicle weight limit of 80,000 pounds for tractor-trailers with a maximum weight of 20,000 pounds per single axle.
See the Virginia DMV and State Police websites for motor carrier safety details and updates.
Washington
Required Vehicle Inspections
Washington follows federal DOT inspection requirements and mandates annual safety checks for commercial vehicles. Documentation must be carried and available during inspections, and drivers must provide roadside inspection reports to the motor carrier within 24 hours.
Equipment Standards
Inspectors verify federal standards for brake systems, tire tread depth, steering integrity, and safety lighting. Washington also monitors the placement and condition of reflective devices.
Emissions or Environmental Testing
Washington State follows CA’s ACT rules regarding emissions. Learn more at the Washington Department of Ecology website.
Roadside Enforcement Authority
The Washington State Patrol Commercial Vehicle Division oversees roadside safety inspections, compliance reviews, and citations under FMCSA guidelines.
Additional Notes or State Resources
Washington’s CVSA-certified inspection program details are available through the WA State Patrol’s official site. Additionally, the Washington State Commercial Vehicle Guide serves as an excellent resource for drivers and fleet managers.
West Virginia
Required Vehicle Inspections
West Virginia requires annual safety inspections for all commercial motor vehicles operating within the state. Trucks must carry proof of a current DOT or state-recognized inspection during roadside checks.
Equipment Standards
Commercial vehicles must meet federal standards for brakes, lighting, tires, steering, and visibility equipment. West Virginia inspectors enforce these rules through on-highway stops and weigh station reviews. Additionally, maintenance records must be kept for at least two years at the operator’s principal place of business.
Emissions or Environmental Testing
West Virginia requires emissions testing for some vehicles, but it’s not a requirement for all CMVs. It’s more common for fleets with nine or more vehicles over 14,000 pounds to have self-inspection and certification requirements related to state smoke opacity standards.
Roadside Enforcement Authority
The West Virginia Public Service Commission Transportation Enforcement Division and WV State Police oversee commercial vehicle inspections and enforcement of FMCSA rules.
Additional Notes or State Resources
Visit the West Virginia DOT Motor Carrier Division website for inspection forms, requirements, and enforcement updates.
Wisconsin
Required Vehicle Inspections
Wisconsin follows federal DOT inspection guidelines and requires annual safety inspections for commercial vehicles operating across state lines. Records must be retained and available upon request.
Equipment Standards
State enforcement checks for brake functionality, lighting system compliance, tire condition, and other federally mandated standards. Load securement and steering components are closely monitored.
Additionally, drivers must perform rigorous self-inspections. They must conduct pre-trip inspections to identify any defects or necessary repairs. These inspections should be done within the first 50 miles of a trip and then again at either the three-hour mark, after 150 miles driven, or after changing their duty status (whichever point comes first).
Emissions or Environmental Testing
Semi-trucks with a GVWR of 14,001 lbs+ are not subject to annual emissions inspections in WI. However, they are required to adhere to smoke opacity standards. All heavy-duty diesel vehicles with a GVWR of 18,000 lbs+ must be tested for smoke emissions annually at a licensed site.
Roadside Enforcement Authority
Wisconsin State Patrol Commercial Motor Vehicle Inspectors conduct compliance checks at weigh stations, roadside stops, and through random audits.
Additional Notes or State Resources
The Wisconsin DOT website offers details on commercial motor vehicle safety regulations and enforcement procedures.
Wyoming
Required Vehicle Inspections
Wyoming requires annual DOT inspections for commercial motor vehicles. Interstate drivers must carry inspection documentation onboard and present it during roadside evaluations.
Equipment Standards
Wyoming follows federal truck brake and tire rules, along with lighting and reflective marking specifications. Inspectors assess load securement and undercarriage safety components to ensure compliance with regulations.
Emissions or Environmental Testing
Wyoming does not require annual emissions tests for heavy-duty vehicles, but it does have specific opacity limits for diesel engine emissions and requires measures to minimize fugitive dust. Learn more at the Wyoming Department of Environmental Quality website.
- Wyoming Smoke Opacity Limit: 30%
- If a Wyoming truck fleet operates in California, it must comply with California’s Clean Truck Check program.
Roadside Enforcement Authority
The Wyoming Highway Patrol oversees commercial vehicle enforcement and has the authority to perform inspections, issue citations, and order out-of-service actions.
Additional Notes or State Resources
Commercial trucking details, laws, and updates are listed on the Wyoming Highway Patrol Commercial Carrier Portal.
Truck Maintenance Laws by State: The Bottom Line
Understanding truck maintenance laws by state helps drivers and fleet managers stay compliant, avoid violations, and prevent costly downtime. Stay ahead of inspection issues and mechanical failures by keeping up with required maintenance. Visit a LubeZone Truck Lube Center near you for fast, affordable preventive services and DOT inspections.
LubeZone is the fastest growing dedicated semi-truck service in the United States with locations in Texas, California, Oklahoma, North Carolina and Georgia. Our preventative maintenance solutions are designed to get the professional driver back on the road FAST.
