TL;DR
The short answer: There is no single nationwide overhang maximum. For commercial motor vehicles subject to 49 CFR 393.87, a load projecting more than 4 feet behind the vehicle or more than 4 inches beyond its sides requires warning flags at least 18 inches square. This is a marking rule, not permission to exceed state size limits. Applicable state rules, vehicle configuration, load type, route, and permit conditions determine whether a movement is legal. See 49 CFR §393.87.
This is a planning guide, not a permit determination. Limits can change based on vehicle configuration, load type, route, and permit conditions. Confirm current requirements with each state’s DOT, DMV, or permit office before you dispatch.
A quick note on terminology: we use oversize as the primary term throughout this guide for a load that exceeds standard legal dimensions. You’ll also see overdimensional used interchangeably in some state statutes and by DOT permit offices — it means the same thing. Overhang is a narrower term that refers specifically to the portion of a load extending beyond the front or rear of the trailer, which is what this guide covers.
At Cowtown Logistics, we specialize in the nuances of oversize freight trucking services. This guide covers the federal baseline, how states define and enforce their own rules, key limits for the most active freight corridors, and what to do when your load crosses multiple state lines.
Trailer overhang, at its core, represents the portion of a load extending beyond the rear (or front) of a vehicle, most notably flatbed trailers. This seemingly straightforward concept carries a significant amount of regulatory weight, governed by a mix of federal and state laws. To navigate these legal dimensions, you’ll need an in-depth understanding of terms like the “legal overhang limit,” “rear overhang limitation,” and “maximum overhang.” Applicable length and projection limits depend on the vehicle configuration, load, and road network.
Federal marking rules and state size rules answer different questions. 49 CFR §393.87 specifies warning flags for covered projections; §393.11 separately specifies lamps and reflectors. Neither is an oversize permit. State length rules and configuration-specific exceptions still apply.
Companies that frequently ship goods using flatbed trailers need to be especially conscious of these laws. If you fail to adhere, it can lead to costly delays, especially if the overhanging loads cross state lines without meeting each state’s specific requirements. A company consistently shipping goods without abiding by the legal rear overhang can see costly delays occur frequently.
Every type of load, from end-to-end overhangs to loading multiple pieces on a flatbed trailer, must respect the maximum length regulations. The total length, including the vehicle length and the load length, is crucial. It’s not just about meeting the legal length requirements but ensuring the cargo is properly secured. Overhangs that aren’t secured properly could potentially damage other vehicles on the roads, so there’s very little room for error.
The regulations surrounding how far something can project off a truck are a mix of federal marking rules and state-specific size and permit rules. Federal guidance addresses when projecting loads need warning devices, while states decide many of the route-specific maximums, permit thresholds, and exceptions for certain load types. Whether concerning a truck or a flatbed trailer, the rules around legal overhang often come about in several ways:
You’ll need to refer to the respective state’s Department of Transportation, DMV, or permit office for the nuances of these rules and to understand which limits actually apply to your load.
For covered commercial vehicles, flags are required when rear projection exceeds 4 feet or side projection exceeds 4 inches. Use the flag sizes and placement in §393.87, together with the lighting requirements in §393.11. State minimums can differ: TxDMV’s permit equipment guidance lists 12-inch red flags. That does not reduce the 18-inch minimum for projections covered by §393.87. A state may also use a different trigger: California requires rear marking at 4 feet or more.
The table summarizes selected state rules and the configuration checks needed for ordinary freight. It is not a 50-state permit chart. An exception for auto transporters, indivisible materials, or a designated road does not automatically apply to another load. A listed limit is not a guarantee that a permit is available above it.
| Jurisdiction | Ordinary limits and relevant exceptions | What to check before seeking a permit | Source |
|---|---|---|---|
| Federal baseline | Covered CMVs: flags at least 18 inches square for rear projection over 4 ft or side projection over 4 in; separate lighting rules apply | Marking does not authorize excess size or replace state permits | 49 CFR §393.87; §393.11 |
| California | Rear projection from the last point of support is generally limited to two-thirds of the defined wheelbase; front projection generally to 3 ft from front tires or bumper. Special cargo exceptions apply. | Apply the STAA/load-confinement rules and cargo exceptions before treating 75 ft as a permit trigger. | Caltrans overhang guidance |
| Texas | TxDMV lists ordinary overhang limits of 3 ft front and 4 ft rear, subject to applicable exceptions. | Excess projection generally needs authorization. Published permitted limits of 25 ft front / 30 ft rear are not automatic permission; route and permit conditions govern. | TxDMV size limits |
| Florida | Ordinary front projection is limited to 3 ft; rear projection must be evaluated under the applicable vehicle-and-load length rule and cargo exceptions. | Over 48 ft is not an automatic semitrailer permit trigger: §316.515(3)(b) provides conditional operation through 57 ft, with axle-position, equipment, and road restrictions. | Fla. Stat. §316.515 |
| Georgia | GDOT identifies 53 ft as the standard trailer-unit length, not the overall truck-tractor combination length. | Check road designation and single-piece extendable-trailer conditions; GDOT lists distinct rules for Interstate/NHS and other state routes. | GDOT size guidance |
| Illinois | Ordinary front projection is limited to 3 ft from front wheels or bumper; rear projection is also constrained by loaded-semitrailer limits and exceptions. | Class I/II combinations have no overall length limit when statutory conditions are met; 53 ft applies to the semitrailer with load. Axle position and non-designated-road rules also matter. | 625 ILCS 5/15-107 |
| Ohio | Ordinary commercial tractor-semitrailer length is governed by a 53 ft semitrailer rule, with or without load; special vehicle and commodity exceptions apply. | Check §5577.05 configuration rules and route restrictions. Auto/boat transporter projection allowances do not establish an ordinary flatbed allowance. | Ohio Rev. Code §5577.05 |
| Pennsylvania | Front projection generally may not exceed 3 ft. The 6 ft rear rule covers a vehicle operated alone and divisible loads on the rear vehicle of a combination. | Nondivisible loads on the rear vehicle of a combination are excluded from that 6 ft rule; overall length requirements under §4923 still apply. | 75 Pa.C.S. §4924 |
| Tennessee | Standard truck-tractor/semitrailer operation uses kingpin-to-rearmost-trailer-or-load and axle-position rules. | Check §55-7-201’s configuration-specific distances and highway provisions; auto-transporter allowances are a separate category. | TDOT statutes and rules: §55-7-201 |
| Colorado | CDOT’s permit selection guidance lists legal overhangs of 4 ft front and 10 ft rear. | Check all loaded dimensions and the specific equipment and route before applying for a permit; these figures alone do not establish route clearance. | CDOT permit selection |
| South Dakota | Loads or retractable extensions may project up to 3 ft beyond the front bumper, bed, or body and 4 ft beyond the rear. | Review permit requirements if those projections or other applicable dimensions are exceeded. | South Dakota vehicle size guidance |
| Oklahoma | FHWA lists a grandfathered semitrailer length of 59 ft 6 in for truck-tractor/semitrailer operation on the National Network and reasonable access routes. | This is a semitrailer-length provision, not a cargo-overhang allowance. Confirm off-network access and load-specific permit requirements with ODOT. | FHWA grandfathered lengths and ODOT permits |
| Kansas | Ordinary front projection is limited to 3 ft from front wheels or bumper. The 4 ft front / 6 ft rear allowance in §8-1905(b) covers vehicles transporting motor vehicles. | Do not use the motor-vehicle transporter allowance for ordinary freight; check applicable loaded length and route requirements. | K.S.A. §8-1905 |
| Missouri | Section 304.170 distinguishes ordinary truck-tractor/semitrailer operation from auto/boat transporters and other combinations. | The 60 ft combination rule has an Interstate exception; qualifying semitrailers are limited to 53 ft. Designated routes and access provisions affect application. | Mo. Rev. Stat. §304.170 |
| New York | Section 385 sets configuration-specific length rules; auto/boat transporter overhang allowances are not a general freight allowance. | Semitrailers over 48 through 53 ft may qualify on designated highways subject to axle position and equipment requirements. The 65 ft combination rule also has highway and cargo exceptions. | N.Y. Veh. & Traf. Law §385 |
Cowtown Logistics coordinates oversize freight shipping across all 48 continental states. See our freight coverage for Texas, California, Florida, Georgia, Illinois, Ohio, Pennsylvania, Tennessee, Colorado, and more.
The table links directly to the state agencies and statutes used for these notes. For the federal requirements, see 49 CFR §393.87, §393.11 Table 1, and FHWA vehicle-size guidance. Federal rules protect qualifying truck-tractor/single-semitrailer combinations from overall vehicle-length caps on the National Network and reasonable access routes; that does not remove applicable trailer, load, or route restrictions.
Before you dispatch a load with any front or rear overhang, confirm each of these for every state on the route:
Securing and managing overhangs, especially on flatbed trailers and larger vehicles, requires diligent attention to safety. To ensure road safety and smooth transport, keep the following in mind:
For commercial motor vehicles subject to 49 CFR 393.87, rear projection of more than 4 feet or side projection of more than 4 inches requires red or orange fluorescent warning flags at least 18 inches square. The section sets marking requirements, not a maximum overhang or a permit exemption. State requirements and any applicable federal exemptions must also be checked.
Measure the projection from the reference point specified by the applicable rule; the trailer edge, bumper, and taillamps are not interchangeable. Section 393.87 refers to projection beyond the vehicle’s rear or sides. California’s rear marking rule measures from the taillamps, while its rear-load limit measures from the last point of support and uses a defined wheelbase. Record both the projection and total loaded dimensions.
Caltrans measurement guidance.
Front and rear projection rules can differ, and transporter-specific allowances do not automatically apply to ordinary flatbed freight. For example, Texas lists ordinary front and rear overhang limits of 3 and 4 feet respectively, while California uses a wheelbase-based rear-load rule. Confirm the vehicle configuration, measurement points, and exceptions for each state on the route.
Texas size limits · Caltrans overhang rules.
If a load exceeds an applicable ordinary overhang or length limit and no exception applies, it must be reconfigured or obtain an available oversize permit before movement. Permit eligibility is not automatic. Approved routes, travel times, escorts, and other conditions depend on the issuing jurisdiction and permit type; a multi-state move needs authorization wherever the load requires it.
FHWA permit guidance · Texas single-trip conditions.
For a rear projection covered by 49 CFR 393.87, use warning flags at least 18 inches square: one at the extreme rear if the projecting load is no more than 2 feet wide, or two positioned to show its maximum width if wider. For rear projections of more than 4 feet, §393.11 Table 1, footnote 10 also requires, when headlamps must be used, a red side-marker lamp on each side and two rear red lamps plus two rear red reflectors. Lamps and reflectors are not interchangeable, and §393.87 does not say to remove flags at night. For side projections over 4 inches on covered vehicles, §393.11 Table 1, footnote 9 requires an amber lamp at the forward outer edge visible from front and side, and a red lamp at the rear outer edge visible from rear and side during headlamp-use hours. Projections no more than 3 feet from front to rear instead use one amber lamp visible from front, both sides, and rear, or one red lamp if at or near the rear. Check state marking rules and permit conditions too.
Federal flags · Lamps and reflectors.
Penalties vary by state, but common consequences include citations, fines, out-of-service delays, permit violations, and liability exposure if an improperly marked or unsecured overhang creates a safety issue. If the load crosses multiple states, enforcement risk increases because each jurisdiction can apply its own rules.
Start by confirming the load’s total dimensions, rear overhang, securement method, and route before dispatch. Then review each state’s permit and marking requirements, including when flags, banners, or lights are required — and confirm whether the state’s published overhang figure actually applies to your trailer configuration, since several states only codify overhang allowances for auto or boat transporters. Many shippers work with an experienced oversized freight provider to coordinate route-specific compliance before the truck hits the road.
Ensuring compliance with overhang regulations is more than just abiding by the law; it’s about safeguarding every journey. But you don’t have to go through this process alone. As your dedicated partner in oversize freight shipping and heavy haul trucking, Cowtown Logistics specializes in managing flatbed and over-dimensional loads. Contact us today for a free quote and let us help you plan a safe, compliant move.
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