Missouri OS/OD Overview
Permit Required
Yes – all oversize or overweight loads require a permit from the Missouri Department of Transportation (MoDOT).
Legal Limits (Without Permit)
- Width: 8'6"
- Height: 13'6"
- Length: 53' trailer; 65' overall (combo)
- Weight: 80,000 lbs GVW
Permitted Load Maximums (Typical Upper Limits)
- Width: Up to 16' with escorts
- Height: Over 15'6" requires route survey and utility clearance
- Length: Over 130' requires review
- Weight: Over 160,000 lbs with axle spacing and bridge analysis
Superloads require review by MoDOT’s Bridge Division and may take longer to approve.
Travel Hours
- Standard: ½ hour before sunrise to ½ hour after sunset
- Weekend: Allowed for loads under 12' wide and 90' long; wider/longer require review
- Holidays: No travel on major holidays or after noon the day before
- Night travel: Rarely allowed; must be specifically authorized
Escort Requirements (General Guidelines)
| Dimension | Escort Requirement |
|---|---|
| Width > 12' | 1 Escort (front or rear depending on roadway type) |
| Width > 14' | 2 Escorts (front and rear) |
| Height > 15'6" | High pole car and route survey required |
| Length > 130' | 2 Escorts recommended |
Additional Notes
- “Oversize Load” signs, red/orange flags, and amber beacon lights are required
- Bridge restrictions, detours, and height clearances must be checked on permit route
- Permits issued via MoDOT’s MODOT Carrier Express System
Detailed Information
PERMITS: Permits valid for seven days. Must have permit prior to entering the state.
OPERATING TIME: One-half hour before sunrise to one-half hour after sunset, including Saturday and Sunday, except that loads over 14 feet wide will not be allowed weekend travel. Travel times are more limited in metropolitan and tourist areas (see Restricted Travel section below). Overweight only up to 112,000 pounds gross with legal size may travel 24 hours except metro and tourist areas.
RESTRICTED TRAVEL: No travel on major Holidays, and from noon the day before these holidays or holiday weekends. No travel weekdays from 6:30 a.m. to 9:00 a.m. and 3:30 p.m. – 6:30 p.m., in St. Louis city and county (except for route 370), St. Charles County on I-70, route 94 and route 40/61 and , and Jefferson County on I-55 and on routes 21, 30, 141 and 61/67. No travel from 7:00 a.m. to 9:00 a.m. and 4:00 p.m. – 6:00 p.m. in the Kansas City area on routes 150, 291, I-470, 291, 152 west to I-435 and inside the area bounded these routes, and inside the city limits of Springfield except on I-44 and Route 65. These metro area curfews do not apply to loads that are overweight only. No permit movement is allowed on Mississippi River bridges in St. Louis on I-70, I-55, I-64 and on route 60/62 to Cairo, IL. During the tourist season, Saturday and Sunday travel are not allowed on routes in Lake of the Ozarks and Branson (within 10 miles of Branson), with the exception of route 65 in Branson area. Tourist season means June 1 through Labor Day at Lake of the Ozarks and through October 31st in Branson area. These curfews are listed in more detail in part 9 of the MO Permit Regulations Booklet, which is available to drivers and should be carried if you do O/D loads in Missouri.
LEGAL DIMENSIONS: Width: Height: 8'6" on Interstate, designated highways; 8' on other roads 14' on designated highways, 13'6" on other roads. Over height loads must be on drop-deck trailer to be permitted. Length: 53' semi-trailer and load (including rear overhang) on Interstate and designated highways; 60' when more than 10 air miles from designated system. Weight: 80,000 Gross Single – 20,000 (22,000 on secondary) Tandem – 34,000 (36,000 on secondary) Tridem – 34,000 (8' of spacing), 42,500 (9' of spacings) Note: Missouri will not give a permit for legal gross weight, but overweight on an axle group.
ROUTINE PERMIT LIMITS: Width: 16' Height: 16' (15'7" maximum on some routes) Length: 150' Weight: 5 axles – 104,000 6 axles – 120,000 7 axles (1-3-3) – 130,000 Single – 20,000 Tandem – 46,000 (40,000 on a 10' spread) Tridem – 60,000 Quad – 72,000 Note: A 1-2-2-1 (tandem drive tractor, tandem trailer and booster) combination is not permittable in Missouri. You must have a Tridem drive tractor to use a tandem trailer and a booster. Loads exceeding these dimensions or gross weight over 160,000 pounds are considered as Super Loads.
ESCORTS: Width: Over 12'4" – 1 escort (2 escorts off designated highway system); over 14' – 1 escort on Interstate and divided highways, 2 escorts required on 2-lane and undivided highways Length: Over 90' – 1 escort on all highways except divided highways Height: Over 15'6" on 2-lane & undivided, and over 15'6” divided highways – route survey and 1 escort with high pole. Utility bucket truck may be required to lift wires.
MISCELLANEOUS: If trailer is stretched, Missouri wants to know how much used and unused space is in well, and on front and rear decks.
SIGNS, FLAGS & LIGHTS: "Oversize Load" signs are required on front and rear of the load vehicle when width exceeds 10'6", and on the rear of the load when overall length exceeds 90'. Flags are required at the extreme ends or projections of all overwidth and overlength loads.