What is a route survey for oversize loads?
A route survey is a pre-trip inspection of the planned route by a certified pilot car operator or specialty engineering firm to confirm the oversize load can physically pass through every point on the route. The survey checks bridge clearances, overhead obstructions, lane widths, turn radii, and any infrastructure constraints. Required for non-standard routing and most superload moves.
Route surveys are required when the planned route deviates from state-pre-approved oversize corridors, when the load configuration is unusual enough to warrant verification, or when the load qualifies as a superload. The survey is conducted before the actual move — typically 5-15 days in advance — and documents every potentially-restrictive point along the route with photographs, measurements, and clearance calculations.
The survey output is a route survey report — a multi-page document with a route map, clearance measurements at every constraint, photographs of bridges and overhead structures, and a recommended travel approach (specific lane positioning, speed restrictions at clearance points, alternate routing if needed). The state DOT reviews the survey as part of the permit application; an inadequate survey can delay or prevent permit issuance.
Route surveys are typically performed by certified pilot car operators (smaller routing) or by specialty engineering firms (larger superload routing). Cost runs $200-$500 per state for standard route surveys and $500-$2,000+ for superload route surveys involving engineering review. The carrier pays the survey cost separately from the state DOT permit fee.
Some states maintain pre-approved oversize corridors that don't require route surveys for standard configurations. For routine oversize work staying on these corridors, carriers can move without paying for route surveys on every trip. Non-standard routing (off-corridor moves) and superload moves are where route surveys add cost; routine flatbed oversize work staying on approved routes typically does not require surveys.