Permits
Iowa oversize permits are valid for five days. Must obtain permit before entering state.
Operating Time
- Permitted vehicles up to 100′ in length, 11′ width, 14′-6″ height and permitted axle limits may have continuous travel seven days a week (24/7), provided travel is on roadway with a minimum width of 22 feet and minimum lane width of 11 feet, and with safety lighting as specified on Iowa provisions sheet.
- Larger loads may travel one-half hour before sunrise to one-half hour after sunset, including Saturdays and Sundays.
Restricted Travel
Des Moines I-235 travel prohibited from 7:00 am – 9:00 am and from 4:00 pm – 6:00 pm Monday through Friday. Other highways in Des Moines can be included under the curfew at officer’s discretion if traffic is heavy. Check for any holidays or holiday weekend travel restrictions.
Legal Dimensions
Length: 53′ semi-trailer and load. (Overhang which results in over 53′ semitrailer and load length is not legal without permit. Steel pipe, beams and constructions materials aren’t exempt.)
Width: 8′-6″
Height: 13′-6″
Weight: 80,000 Gross
Single – 20,000
Tandem – 34,000
Tridem – 42,000 (w/ minimum 8′-1″ axle spacing)
Routine Permit Limits
Length: 120′
Width: 18′
Height: 18′
Weight:
Single – 20,000
Tandem – 46,000
Tridem – 60,000
Quad – 80,000
Steer Tire: Permit does not break out the steer axle weight but enforcement goes by the single (steer) tire weight rating (on the side of the tire) times two. You must be licensed for as much as you wish to permit in Iowa.
Loads exceeding these dimensions or weight are considered as super loads.
Escorts
On all highways:
Length:
Over 85′ – one escort or amber revolving light
Over 120′ – one escort
Overhang: Front projection over 25′ or rear over 10′ – one escort or amber revolving light or
strobe light on rear of load for rear overhang over 10′).
Height: Over 14′-6″ – one escort with high pole.
On 4-lane roadways:
Width:
14′-6″ to 16′-6″ – one rear escort or two amber revolving or strobe lights (one on power unit, one on rear extremity of vehicle or load)
Over 16′-6″ on 4-lane roadways – one escort.
On 2-lane highways:
Width:
When width exceeds one-half of roadway width up to and including 14′-6″ – one front escort
Width over 14′-6″ – one escort. An amber or strobe light on the power unit and on the rear extremity of the vehicle or load may be used instead of an escort if the width is up to and including 14′-6″ and exceeds one-half of the roadway and lane width is 12′ or more with sufficient shoulders
Miscellaneous
Blades, buckets, counterweights, etc. do not have to be removed when the load is just over dimension. If the load is overweight, they must be hauled separately.
Signs, Flags & Lights
“Oversize Load” signs and flags are required when a vehicle and load exceeds 75′ in length, 8′-6″ width, and/or 14′-4″ in height. Flags are required for rear overhang exceeding 4 feet on all permitted vehicles/loads. Flags should be mounted at each front corner of the towing unit, at each rear corner of the load, and at any wide points or protrusions of the load. An amber revolving light at least 7″ high and 7″ in diameter is required on the towing unit whenever length exceeds 85′, front overhang exceeds 25′ or rear overhang exceeds 10′ (light should be on the load in the rear) or weight exceeds 80,000 lbs. An escort can be used in lieu of amber light.
