4 min read

General OS/OW Info

General OS/OW Info

Our nation's roadways are capable of carrying OS/OW loads through trucks that transport heavy machinery, prefabricated construction components, and hundreds of other large products.

OS/OW Loads Definition:

By definition, an oversize load is any combination of vehicle and load that exceeds one or more of the legal maximum width, height, and/or length specifications. The majority of these loads are "irreducible," meaning they cannot be easily divided into smaller components that fit within the parameters of a "normal" load.

The dimension that is most frequently surpassed is width. The national system of Interstate and other major US highways, features driving lanes that are 12’ or wider. This provides a nearly two-foot space on either side of a vehicle or load that is 8’6’’ wide—the maximum legal width in all states. Any load wider than 8’6’’, for example, a bulldozer with a blade wider than 10’, is considered an oversize "wide" load, and hauling that bulldozer on public roadways requires a permit and particular safety requirements.

Along with excessive width, an oversize load can also be defined by excessive height and/or length. However, there are no universally recognized legal standards for height or length. For instance, the normal legal state's maximum height is between 13’6’’ and 14’6’’, while lawful overall lengths can exceed 75 feet under some circumstances. Please keep in mind that this topic pertains to loads that will require a permit to carry. There are instances where a load exceeds the permitted length, however the load must be designated with safety flags in order to perform the load transportation as safely as possible.

Additionally, overweight loads may be oversized. Contrary to popular belief, this is not true. Overweight goods can readily fit into the bed of a conventional truck, such as a gravel hauler or typical 43-foot trailer. Federal maximum gross vehicle weight for legal loads is 80,000 pounds, which is further restricted by axle weight limits of 20,000 pounds for a single axle and 34,000 pounds for a tandem axle.

While over-width loads may provide a threat to other traffic, overweight vehicles may cause significant damage to the highway infrastructure and bridges if the gross weight and/or weight-per-axle exceed the roadway's load carrying capacity.

There are various restrictions, including the prohibition of mobility on holidays, weekends, and, in some situations, the days immediately preceding or following a holiday, in recognition of the likelihood of increased public travel on those days.

Oversized loads can obstruct normal traffic flow, close lanes, and cause delays. Numerous municipalities prohibit the transit of big loads during normal business hours or near schools.

States are responsible for staffing and providing facilities for permit issuance, maintaining and operating state inspection stations and scales, and enforcing regulations governing the transportation of oversize vehicles.

Along with trucking companies and its operators, there are brokers who contract their services, as well as businesses that support oversize carrying activities, such as distributors of safety equipment and signs and contract escort vehicle operators.

Federal and State Regulations

To safeguard and sustain the nation's transportation system, the Federal Government establishes size and weight regulations through the Code of Federal Regulations (CFR) and the Federal Highway Administration (FHWA). Enforcement of oversize/overweight regulations for carriers is managed by State Administration.

Fun Fact: The US National Road Network includes about 200,000 miles of major roads.

Each state is responsible for its own set of highway regulations. Each state is responsible for ensuring that commercial motor vehicles—trucks, buses, and truck-tractor-trailers—conform to both state and federal regulations. Additionally, many state roads are not constructed to Federal standards and may be unable to safely transport oversize or overweight cargoes. As a result, individual governments impose their own restrictions on the size and weights of various types of roadways. For example, local two-lane roadways may not be capable of securely transporting cargo wider than 8'.

The permitted dimensions and weights vary by state, and vehicles that exceed the legal dimensions typically require a permit specifying the size, weight, and type of the load, as well as its origin and destination. Permit fees are based on the nature of the load and vary by state. Typically, the permit outlines the route the load must take, as well as the dates and times the load may travel and the appropriate safety equipment.

Oversize/overweight permits in two easy steps:

(1) verify that the load can be transported safely and lawfully from its origin to destination.

(2) acquire the requisite state permits to transport the load.

Prior to hauling larger oversize loads, such as those with widths up to 15 feet or heights greater than 13’6’’, a route analysis may be necessary. It must be established that overhead power lines, bridges and overpasses, and overhead signs do not represent a hazard to pass. For overweight loads, it must be established that vehicles do not place excessive strain on bridges and overpasses and that weight is distributed evenly across the axels to safeguard roadways.

States frequently establish precise standards about travel times, weather conditions, required safety equipment, and permit fees. Additionally, varying load lengths and weights may demand the use of alternative routes, safety equipment, operating hours, and the necessity of doing a pre-trip highway assessment.

Numerous oversize/overweight loads are one-time events that require a permit. The process of obtaining the required permit may take several weeks, depending on the state and the nature and size of the load. If the load will travel across many states, the operator must apply for and get permits in each state. Typically, these permits are issued for specific travel dates. It is vital that applications are submitted well in advance, as getting the necessary licenses may take several weeks.

See also:

Oversize Transport Regulations

OS/OW Civil Escorts

Municipal OS/OW OPS Info

DOT Checklist

Order Permits