Flatbed Trailer

The flatbed trailer is an open-deck platform without sides, roof, or enclosure. That openness is both the defining advantage and the primary operational consideration: freight can be loaded from the sides, rear, or even overhead by crane or forklift, making flatbed the go-to choice for long, heavy, or irregularly shaped cargo that simply won't fit in a box trailer. A standard 48 or 53 ft flatbed deck sits approximately 5 feet above the ground. With a maximum legal height of 13 ft 6 in, that leaves roughly 8.5 feet of usable cargo height above the deck — enough for most construction and industrial freight. Payload capacity is higher than dry van at up to 48,000 lb, because flatbed trailers are structurally simpler and lighter than enclosed trailers. Cargo securement is the most critical operational element. FMCSA 49 CFR Part 393 specifies minimum tie-down requirements by commodity — steel coils, for example, require a different securement approach than lumber or machinery. The Working Load Limit (WLL) of all chains, straps, and binders must exceed the requirements for the cargo weight and geometry. Edge protectors must be used to prevent straps from cutting into cargo or weakening under load. Tarping is a separate skill set. Many flatbed loads — steel, lumber, and building materials in particular — require weather-protective tarps that must be rigged, tensioned, and secured properly. Tarp rigs vary from simple single-piece lumber tarps to multi-piece machinery tarp systems. Some shippers provide pre-tarped or shrink-wrapped loads; most require the driver to tarp. Oversize loads (exceeding 8.5 ft wide, 13.5 ft tall, or 80,000 lb gross) require permits and may require pilot cars, route surveys, and nighttime travel restrictions.

Dimensions and payload

Typical length48–53 ft
Typical width8.5 ft (102 in)
Typical heightDeck height approximately 5 ft above ground; max legal cargo height 13.5 ft total (leaves ~8.5 ft above the deck)
Payload capacityUp to 48,000 lb

Typical use cases

  • Construction materials — steel, lumber, rebar, concrete pipe
  • Heavy machinery and equipment delivery to job sites
  • Oversized freight that cannot fit in an enclosed trailer
  • Agricultural equipment and implements
  • Wind energy components (tower sections, nacelles, blades with oversize permits)

Common freight types

  • Steel coils, beams, and plate
  • Lumber and dimensional timber
  • Concrete products (pipe, blocks, precast panels)
  • Heavy machinery and industrial equipment
  • Agricultural equipment
  • Roofing materials and building panels
  • Pipe and conduit
  • Military equipment
  • Mining equipment
  • Modular building components

Special considerations

  • All cargo must be secured per FMCSA 49 CFR Part 393 — chains, binders, straps, edge protectors, and blocking as appropriate for commodity type. Flatbed loads are inspected by DOT roadside inspectors far more frequently than enclosed trailers.
  • Many flatbed loads require tarping to protect cargo from weather and road debris — tarp work is physically demanding and adds significant loading time. Shippers should factor tarp labor into appointment windows.
  • Oversize or overweight loads require state-by-state permits, escort vehicles (pilot cars), and sometimes law enforcement accompaniment — lead times can range from same-day to several weeks depending on states traversed.
  • Height, width, and weight must be measured and declared accurately before dispatch. Exceeding permit dimensions can result in significant fines and carrier disqualification.
  • Flatbed drivers require additional skills and physical fitness compared to dry van — tarping, load securement certification, and working at deck height are all required competencies.

New 48–53 ft flatbed trailers typically range from $20,000–$35,000. Per-mile spot rates are generally 10–20% above dry van due to securement labor and equipment specificity.

Frequently asked questions

What is the difference between a standard flatbed and a step deck or double drop?

A standard flatbed has a single-level deck approximately 5 ft off the ground, which limits cargo height to about 8.5 ft. A step deck adds a lower rear section to accommodate taller cargo. A double drop has a lowered well in the middle for even taller freight. If cargo exceeds 8.5 ft but does not require the load to roll on, a step deck or double drop is typically the solution.

Does all flatbed freight need to be tarped?

No. Tarping requirements depend on the commodity and shipper/receiver specifications. Steel (hot-rolled coils, plate) is often shipped without tarps. Lumber, building materials, and machinery parts typically require tarps. Some shippers specify tarp type (lumber, machinery, or smoke tarp) in the load requirements.

What cargo securement regulations apply to flatbed loads?

FMCSA 49 CFR Part 393, Subpart I governs cargo securement for all CMVs. Specific commodity tables cover steel, logs, lumber, heavy vehicles, and other common flatbed freight. All tie-down devices must have a Working Load Limit rating at least half the weight of the cargo being secured.

How long does permitting take for oversize flatbed loads?

Single-state permits for loads up to the state's "superload" thresholds are often available same-day or next-day online. Multi-state routes and truly heavy/wide loads can take days to weeks — especially if route surveys, bridge analyses, or law enforcement coordination are required. Plan accordingly for time-sensitive deliveries.

What is a conestoga or curtainside trailer?

A conestoga (also called a rolling tarp system or curtainside) is a flatbed variant with a retractable tarp system on a frame. It provides side and top weather protection like a dry van while allowing side-loading like a flatbed. It is popular for sensitive freight (machinery, steel that must stay dry) that also needs forklift side access.