State law chart
Trailer Breakaway Requirements by State
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Quick answer
35 of the 50 states in this dataset have a breakaway requirement on file. In 14 of them the statute also says the brakes must stay applied for at least 15 minutes. The trigger is usually the weight at which trailer brakes become mandatory, but not always: some states require brakes with no breakaway system, and a few set the breakaway rule at a higher weight. 6 states have not yet had their breakaway rule read from a statute and are marked as needing verification.
Breakaway requirement by state
| State | Breakaway requirement | Brake threshold | Rule detail |
|---|---|---|---|
| Alabama | Yes | 3,000 lb | Ala. Admin. Code r. 760-X-1-.09(d) |
| Alaska | Yes | 5,000 lb | 13 AAC 04.205(d)(2) |
| Arizona | Yes | 3,000 lb | A.R.S. 28-952(A)(3) |
| Arkansas | Yes | 3,000 lb | Ark. Code 27-37-501(c) |
| California | Yes | 1,500 lb | Cal. Veh. Code 26304 |
| Colorado | Yes | 3,000 lb | C.R.S. 42-4-223(1)(c) |
| Connecticut | Yes | 3,000 lb | R.C.S.A. 14-137-123, 14-137-124, as stated by Connecticut DMV |
| Delaware | No statewide requirement found | 4,000 lb | 21 Del. C. 4305 |
| Florida | Yes | 3,000 lb | Fla. Stat. 316.261(4) |
| Georgia | Yes | 3,000 lb | 49 C.F.R. 393.43 as applied by Georgia DPS Fact Sheet 054; trailer brakes over 3,000 lb per O.C.G.A. 40-8-50(d) |
| Hawaii | Yes | 3,000 lb | Haw. Admin. R. 19-133.2-40(b)(8) |
| Idaho | Yes | 1,500 lb | Idaho Code 49-933(3) |
| Illinois | Yes | 3,000 lb | 625 ILCS 5/12-301(a)(4) |
| Indiana | Yes | 3,000 lb | Ind. Code 9-19-3-3 |
| Iowa | No statewide requirement found | 3,000 lb | Iowa Code 321.430(3) |
| Kansas | No statewide requirement found | See state page | K.S.A. 8-1734; 8-1907(d) |
| Kentucky | No statewide requirement found | See state page | KRS 189.090 |
| Louisiana | Yes | 3,000 lb | La. R.S. 32:341(C) |
| Maine | No statewide requirement found | 3,000 lb | 29-A M.R.S. 1902(4) |
| Maryland | Yes | 3,001 lb | Md. Code, Transp. 22-301(e) |
| Massachusetts | Needs verification | 10,000 lb | — |
| Michigan | No statewide requirement found | 3,000 lb | Mich. Comp. Laws 257.705(1)(c) |
| Minnesota | Yes | 3,000 lb | Minn. Stat. 169.67, subd. 3(b) |
| Mississippi | Yes | 2,000 lb | Miss. Code Ann. 63-7-51(3) (text via Mississippi Legislature bill document) |
| Missouri | Yes | See state page | Rule text on state page |
| Montana | Yes | 3,000 lb | Mont. Code Ann. 61-9-305 |
| Nebraska | Yes | 3,000 lb | Neb. Rev. Stat. 60-6,246(2) |
| Nevada | Yes | 1,500 lb | Nev. Rev. Stat. 484D.250(5) |
| New Hampshire | Needs verification | 3,000 lb | — |
| New Jersey | Yes | 3,000 lb | Rule text on state page |
| New Mexico | No statewide requirement found | 3,000 lb | NMSA 1978 66-3-840(A)(3)-(4) |
| New York | Yes | 3,000 lb | NY DMV MV-529C; brake threshold at NY VTL 375(1)(c) |
| North Carolina | No statewide requirement found | 4,000 lb | N.C.G.S. 20-124(f) |
| North Dakota | No statewide requirement found | See state page | N.D.C.C. 39-21-32(3) |
| Ohio | Yes | See state page | Ohio Rev. Code 4513.20(A)(4) |
| Oklahoma | Yes | 3,000 lb | 47 O.S. 12-301(C) |
| Oregon | No statewide requirement found | See state page | ODOT Towing a Trailer in Oregon (737-3503) p.15; ORS 815.125(3) |
| Pennsylvania | Yes | 3,000 lb | 75 Pa.C.S. 4502(c) |
| Rhode Island | Yes | 4,000 lb | R.I. Gen. Laws 31-23-4(c) |
| South Carolina | Yes | 3,000 lb | S.C. Code 56-5-4850(d), (e) |
| South Dakota | Yes | 3,000 lb | SDCL 32-18-17 |
| Tennessee | Yes | 3,000 lb | Tenn. Code Ann. 55-9-204, per Tennessee Highway Patrol trailer inspection requirements |
| Texas | Yes | 4,500 lb | Tex. Transp. Code 547.405(d), (e) |
| Utah | Needs verification | See state page | Rule text on state page |
| Vermont | Yes | 3,000 lb | 23 V.S.A. 1307(f), (g) |
| Virginia | Yes | 3,000 lb | 19VAC30-70-100 (authority Va. Code 46.2-1165) |
| Washington | Yes | 3,000 lb | RCW 46.37.340(4) |
| West Virginia | Yes | 3,000 lb | W. Va. Code 17C-15-31(a)(3) |
| Wisconsin | No statewide requirement found | 3,000 lb | Wis. Stat. 347.35(3); Wis. Admin. Code Trans 308.01, 305.51 |
| Wyoming | Needs verification | See state page | — |
"No statewide requirement found" means the statute on file was read and contains no breakaway duty. "Not verified as required" means no requirement was confirmed in the sources reviewed; treat it as unverified, not as an exemption. The brake threshold column is the brake rule, which can differ from the breakaway trigger.
What the system actually does
A steel cable runs from the trailer's breakaway switch to a fixed point on the tow vehicle. If the coupler releases, the cable pulls a pin from the switch, which connects the trailer battery to the trailer's electric brakes and applies them. Attach the cable to a fixed point such as a loop on the hitch receiver, not to the safety chains or to the ball mount, which can leave with the trailer.
The battery is the part to check
The breakaway battery sits outside in the weather and on many trailers is charged only while the trailer is plugged into the tow vehicle. A flat battery leaves the system looking normal and doing nothing. Before a trip, with the trailer wheels chocked, pull the pin and confirm the brakes apply, then put the pin back. A charged 12-volt lead-acid battery reads about 12.6 V at rest; a much lower reading means charge or replace it before relying on it.
Routing mistakes that defeat it
Attaching the cable to a safety chain means a separation drags the chain and the cable together, and the pin may never pull. A cable that is too long has the same effect. One that is too short pulls the pin on a tight turn and locks the trailer brakes mid-turn. It should pull before the chains go tight, with enough slack for full turns.
Breakaway does not always follow the brake rule
In most states that require one, the breakaway rule sits in the same statute as the brake rule and starts at the same weight. The statutes on file show exceptions in both directions. Iowa, Maine, Michigan and Wisconsin require brakes on heavier trailers but no breakaway device. Connecticut requires a breakaway device only from 10,000 lb GVWR, and Illinois requires automatic application on breakaway only for towed vehicles over 5,000 lb. Read the rule on the state page for every state you drive through.
Worked example
Pre-trip breakaway test, step by step
A short check in the driveway, with the trailer coupled, the wheels chocked and the tow vehicle's engine off.
| Line item | Weight | Where the number comes from |
|---|---|---|
| 1. Chock the trailer wheels | Both sides | The brakes are about to apply; the trailer must not move |
| 2. Check battery voltage | About 12.6 V at rest | Charged 12 V lead-acid; charge or replace if well below |
| 3. Pull the breakaway pin | Firm, straight pull | Pull in the direction the cable would pull in a separation |
| 4. Try to move the trailer | Should not roll | The trailer battery alone is applying the brakes |
| 5. Reinsert the pin | Fully seated | Confirm the brakes release |
| 6. Check cable length | Pulls before the chains go tight | With enough slack for full turns |
A breakaway system that has not been tested since last season is an assumption. The battery is the part most likely to have gone flat in storage, and this check finds that in the driveway rather than on the road.
Frequently asked questions
What is a trailer breakaway system?
A cable-operated switch that applies the trailer's electric brakes from the trailer's own battery if the trailer separates from the tow vehicle.
Do I need a breakaway system on a small trailer?
Usually only if the trailer needs brakes at all, since most states start both rules at the same weight. A few states set the breakaway trigger at a different weight, and some require brakes without a breakaway system, so check each state page.
Where should the breakaway cable attach?
To a fixed point on the tow vehicle such as a loop on the receiver or frame. Not to the safety chains, and not to the ball or ball mount, which could leave with the trailer.
How long do the brakes have to stay applied?
Where a statute sets a duration, it is 15 minutes: 14 of the states with a breakaway rule on file say so. A charged breakaway battery is what makes that possible.