Missouri Oversize & Overweight Permits

When Missouri needs a permit

Missouri height splits by road: 14' on the interstate, 13'6" elsewhere (Mo. Rev. Stat. 304.170), so a 13'6" load never needs a permit. Cross 8'6" wide or 80,000 lb and you buy an OS/OW permit from MoDOT. Escorts start at 12'6" wide; Highway Patrol rides above 16'. Move in daylight, sit on the six major holidays, and expect bridge analysis past 160,000 lb.

Thresholds, escorts, and curfews

• Legal max before a permit: Permit needed over 8'6" wide, 80,000 lb gross (20,000 lb single axle, 34,000 lb tandem), or the height that applies to your route. Height splits by road: 14' on the interstate and designated system, 13'6" on other highways (Mo. Rev. Stat. 304.170). So a 13'6" load runs permit-free statewide, but 13'7"-14' needs a permit once you leave the interstate. Over-length combinations and any over-width also trip the OS/OW line.
• Escort / pilot car: No escort up to 12'6" wide. One escort for width over 12'6" up to 14' (rear on divided/multilane, front on two-lane). Over 14' up to 16': one rear on divided highways, front and rear on undivided and two-lane roads. Front height-detection vehicle over 15'6". Highway Patrol escort now starts over 18' wide, over 200' long, or over 18' high under the superload escort pilot MoDOT began January 1, 2026; the codified rule at 7 CSR 10-25.020(15)(G)(5) still reads 16' wide on two-lane, 150' long and 17' high, and MoDOT can end the pilot without notice, so confirm before you book a trooper. A rear escort also covers over-length combinations.
• Superload: Superload once you top 16' wide, 16' high, 150' long, or 160,000 lb gross. That kicks in a bridge/roadway analysis fee, a movement-feasibility review, and Highway Patrol escorts, with real lead time before you roll.
• Travel curfew: Oversize moves run from a half hour before sunrise to a half hour after sunset, and stop when road conditions are hazardous or visibility drops under 500' (7 CSR 10-25.020(9)(B)). Over-width loads up to 12'6" can still move at night on a single-trip or blanket permit if the height is legal and the length stays at or under 110' (10)(F), and hay up to 14' wide can move at night as well (10)(E). Overweight loads within those same dimensions are granted day and night movement (11)(A). No oversize movement on New Year's, Memorial Day, July 4th, Labor Day, Thanksgiving and Christmas, from noon on the last business day before the holiday until a half hour before sunrise on the first business day after (1)(I). St. Louis and Kansas City metros add rush-hour limits.
• Permit fee: Single-trip oversize from about $15. Overweight single-trip runs $15 plus $20 per 10,000 lb over legal, and above 160,000 lb adds a bridge/roadway analysis fee of $425 (0-50 mi), $625 (51-200 mi) or $925 (200+ mi). Annual blanket permits roughly $128 (single-commodity oversize) to $624 (overweight round-trip).

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