Towing Laws by State: What Every Driver Needs to Know

Before you hitch up and hit the highway, there’s a set of rules that most towing guides never talk about: the law. Towing regulations vary significantly from state to state, and many drivers are genuinely unaware that what’s legal at home may be a violation the moment they cross a state line. Speed limits, safety chain requirements, lighting, brake laws, length and width restrictions — all of it varies, and the consequences for violations range from a fix-it ticket to a significant fine to being ordered off the road entirely. This guide breaks down the most important towing laws by state and where to find the information that applies to your route.

Important note: This guide is intended for informational purposes and provides a general overview of common towing regulations. Laws change and enforcement varies. Always verify the current requirements for each state you plan to travel through using the official resources linked below. When in doubt, consult your state’s DMV or a legal professional.

Why Towing Laws by State Matter Beyond Just Safety

Towing compliance isn’t just about safety — it’s about liability. If you’re in an accident while towing and investigators find that your trailer wasn’t compliant with state law (wrong ball size, missing safety chains, non-functioning lights), your insurance company may use that as grounds to reduce or deny a claim. In some states, a trailer that’s not properly equipped is considered an illegal vehicle, and liability for any resulting accident may fall squarely on you. This is another reason why the basics — lights, chains, brakes, and proper hitch setup — aren’t optional.

Speed Limits While Towing

Most states have either a universal speed limit that applies to all vehicles, or a separate lower speed limit for vehicles towing trailers. California, for example, has a maximum speed limit of 55 mph for any vehicle towing a trailer — even on interstates where cars travel at 70. Texas has no separate towing speed limit in most zones, but some local and construction speed limits apply. Montana, Wyoming, and Nevada tend to have higher or uniform speed limits. The key takeaway: don’t assume the posted limit applies to you when towing. Check the state’s towing speed rules before your trip, especially if you’re crossing multiple states.

Safety Chain Requirements

Nearly every state requires safety chains between the tow vehicle and trailer — but the specific requirements vary. Most states require crossed chains under the tongue (the X-pattern that cradles the tongue if the trailer detaches). Some states specify minimum chain strength relative to trailer GVWR. A few states require a minimum of two independent chains. The X-crossing requirement is both a legal standard in most states and simply the safest configuration — it’s the right way to attach safety chains regardless of local law. For more on proper hitch setup and safety chain attachment, see our guide on The Pre-Trip Towing Checklist Every Driver Needs.

Trailer Lighting Requirements

Federal law establishes baseline trailer lighting requirements — tail lights, brake lights, and turn signals — that all states adopt. However, longer trailers (typically over 30 feet) require additional side marker lights and reflectors. Trailers over 80 inches wide require side marker lights as well. Most states require that trailer lighting match the tow vehicle’s signals — if your truck signals right, the trailer must also signal right. Electrical failures that leave a trailer running without brake lights or turn signals are both dangerous and illegal in every state. Keep your trailer wiring in good condition and test lights before every trip. Our guide on How to Wire Trailer Lights covers diagnosis and repair.

Trailer Brake Requirements

This is where state laws vary most significantly. Most states require trailer brakes when the trailer’s loaded weight exceeds a threshold — typically between 1,500 and 3,000 lbs depending on the state. California requires brakes on any trailer with a loaded weight over 1,500 lbs. Texas requires them over 4,500 lbs. Washington state requires them over 3,000 lbs. Some states also require a breakaway brake system — a battery-powered emergency brake that activates if the trailer separates from the tow vehicle. If you’re towing a trailer that weighs more than a few thousand pounds and you’re not using trailer brakes, you’re likely in violation of the law in multiple states — and creating a genuinely dangerous braking situation. See our complete guide on Electric Trailer Brakes and Brake Controllers for setup and compliance guidance.

Length, Width, and Height Restrictions

Most states follow federal guidelines that limit combination vehicle length (tow vehicle plus trailer) to 65 feet on most roads, with some exceptions for specific configurations. However, trailer-only length limits also apply — typically 40–53 feet for single trailers. Width is almost universally restricted to 8.5 feet (102 inches) for non-permit loads. Height limits are typically 13.5–14 feet for unpermitted loads. For recreational towing (typical utility trailers, boat trailers, travel trailers, fifth wheels), these limits rarely come into play. But if you’re hauling an oversized load — a wide equipment trailer, a long flatbed — you need to research permit requirements for every state on your route well in advance.

Mirror Requirements

Many states require that a driver have an unobstructed view to the rear of the vehicle — and specifically require towing mirrors when the trailer is wider than the tow vehicle. If your trailer blocks your rear view with standard mirrors, you’re legally required to use extended or towing mirrors in most states. Beyond the legal requirement, towing without adequate rear visibility is genuinely dangerous. See our full guide on Towing Mirrors for recommendations on the right mirror setup for different trailer widths.

Where to Check State-Specific Towing Laws

The most reliable source for current towing regulations in each state is that state’s Department of Motor Vehicles (DMV) or Department of Transportation (DOT) website. Search for “[state name] trailer towing regulations” or “[state name] DMV trailer requirements” to find the relevant statutes. For multi-state trips, the American Automobile Association (AAA) publishes a digest of state towing laws that many members find useful. The Federal Motor Carrier Safety Administration (FMCSA) website covers federal regulations that apply to commercial towing and provide baseline standards that most state laws build on.

The Most Common Violations to Avoid

Based on what law enforcement most commonly cites during towing stops, these are the violations to be most aware of: trailer lights that don’t work (especially brake lights), exceeding towing speed limits (particularly in California), towing a trailer that requires brakes without a brake controller, using safety chains that are too long or improperly attached, and towing a trailer wider than the tow vehicle’s mirrors without extended towing mirrors. All of these are preventable with proper equipment and a quick pre-trip inspection.

The Bottom Line

The law varies by state, and the responsibility for knowing those laws before you cross state lines falls on you as the driver. The good news is that most of the legal requirements — proper lights, working brakes, correct safety chains, adequate mirrors — are also simply the safest way to tow. If your rig is set up correctly for safety, you’re probably already in compliance with most of the law. The areas to double-check before a multi-state trip are speed limits, specific brake weight thresholds, and any size or permit requirements for your trailer type.

TowPro Academy’s truck towing course teaches you the right way to set up and operate a towing rig — which also happens to be the legal way. 55 video lessons for a one-time payment of $50.

Further Reading

• The Pre-Trip Towing Checklist Every Driver Needs
• Electric Trailer Brakes and Brake Controllers: What Every Tower Needs to Know
• Towing Mirrors: Do You Need Them and Which Type Is Right for Your Truck?
• How to Wire Trailer Lights: A Step-by-Step Guide

Read Next

• What Is GVWR?
• Complete Beginner’s Guide to Towing
• Towing Glossary: A–Z Definitions for Every Tower
• New to Towing? Start Here
• Complete Beginner’s Guide to Trailer Towing

Frequently Asked Questions

Do towing laws vary by state?

Yes. States differ on maximum trailer width and length, towing speed limits, braking requirements, safety chain rules, and whether passengers may ride in a towed unit. Always check the laws for every state on your route.

When does a trailer need its own brakes?

Most states require trailer brakes once the trailer’s gross weight passes a set threshold, commonly around 1,500 to 3,000 pounds. The exact weight and brake type required depend on the state.

Are trailer safety chains required by law?

In nearly every state, yes. Safety chains must be crossed under the coupler and rated to hold the trailer’s weight if the hitch fails. Some states also mandate breakaway systems on heavier trailers.

Can passengers ride in a towed trailer or fifth wheel?

It depends on the state. Some allow occupants in fifth wheels with certain safety features, while many prohibit riding in any towed trailer. Confirm the rule in each state you’ll travel through.

Learn More with TowPro Academy

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