Oversize & Heavy Haul
Past a certain size, freight stops being a transport problem and becomes a permitting problem. The truck is the easy part. The route, the paperwork and the calendar are what decide whether the load moves this week or next month.
The Four Numbers That Trigger a Permit
A load is oversize or overweight the moment it exceeds any one of four thresholds, and exceeding one is enough — a load can be perfectly legal on weight and still need a permit in every state it crosses because it is three inches too wide. Width above 8'6", height above 13'6", length beyond the state's limit for the configuration, or gross weight above 80,000 lb all put you in permit territory.
Weight has a second layer. Staying under 80,000 lb gross is not sufficient on its own: the Federal Bridge Formula also governs how that weight is distributed across axles and how far apart those axles sit. This is why heavy haul trailers grow axles rather than capacity — jeeps and boosters added ahead of and behind the trailer spread the same load over more axles and a longer wheelbase, bringing an otherwise illegal configuration back inside the formula.
| Dimension | Common Legal Limit | Beyond It |
|---|---|---|
| Width | 8'6" (102") | Permit; escorts from roughly 12' |
| Height | 13'6" (14' in some western states) | Permit; height pole escort and route survey |
| Length | Set per state and configuration | Permit; rear escort on long overhang |
| Gross weight | 80,000 lbs on the Interstate system | Permit; bridge analysis and axle spread |
Operational Safeguards
Permits Per State, Per Trip
Permits are issued by each state the load crosses, each with its own dimensions, fees, approved routing and validity window. A five-state move is five applications, and one refusal reroutes the whole trip.
Route Survey Before Dispatch
Bridge clearances, weight-restricted structures, overhead utilities, turning radii at the final approach and any active construction are checked against the actual dimensions. The last mile into a plant or job site defeats more oversize loads than the highway ever does.
Escorts Arranged to State Rules
Pilot car requirements are set by each state and scale with width, height and length. Where a police escort or utility crew is mandated, that coordination is scheduled before the permit window opens, not on the day.
Why Heavy Haul Takes Longer Than You Think
Permitted loads generally travel in daylight only. Many states prohibit oversize movement at weekends and on public holidays, and metropolitan areas layer rush-hour curfews on top. A thousand-mile permitted run therefore does not take two days — it takes as many days as the legal driving windows allow, and a holiday weekend in the middle simply stops it.
Superloads sit in a category of their own. Thresholds vary by state, but once a load passes roughly sixteen feet in width or height, or moves into six-figure weights, it typically requires an engineering review, individual bridge analysis and sometimes physical utility work along the route. Those approvals are measured in weeks. Bringing us in at the quotation stage of your project, rather than when the machine is already built and sitting on a pad, is the difference between a scheduled move and an emergency one.
| Equipment | Why It Is Used |
|---|---|
| RGN / Lowboy | Detachable neck lets machinery drive on; lowest deck height |
| Stretch RGN | Extends to support long pieces along their full length |
| Multi-axle with jeeps & boosters | Spreads gross weight to satisfy the bridge formula |
| Perimeter frame trailer | Open centre carries tall or deep-bodied items lower |
| Double drop / stretch double drop | Well depth buys legal height on tall but lighter pieces |
What We Need to Quote
Exact Dimensions and Weight
Not approximate. Permits are issued against stated figures, and a load that measures differently at a checkpoint than it does on the permit is stopped where it stands.
Centre of Gravity and Lift Points
These determine where the piece sits on the deck, how axle weights fall, and how it is rigged. Manufacturer drawings are ideal; a dimensioned sketch is usually enough to start.
Site Access at Both Ends
Gate widths, ground bearing capacity, overhead obstructions and turning space decide whether the final approach is possible at all. Photographs of the approach are genuinely useful.
Start Before the Piece Is Built
Send dimensions, weight and both site addresses. We will tell you what permits the route needs, what escorts it triggers, and how many days the calendar really requires.