PERMITS
Iowa oversize permits are valid for five days and must be obtained before entering the state.
OPERATING HOURS
Loads up to 100 feet in length, 11 feet in width, 14 feet 6 inches in height, and within permitted axle limits may travel continuously, 24/7, on roads with at least 22 feet of overall width and 11-foot lane widths, provided they meet lighting requirements listed on the Iowa provisions sheet. Larger loads may travel from 30 minutes before sunrise to 30 minutes after sunset, including weekends.
RESTRICTED TRAVEL
Travel on I-235 in Des Moines is restricted Monday through Friday between 7:00 AM and 9:00 AM, and from 4:00 PM to 6:00 PM. Other Des Moines roads may also be restricted at an officer's discretion during high-traffic periods. Check for any applicable holiday or holiday weekend restrictions.
LEGAL DIMENSIONS
Length:
- 53-foot semi-trailer and load
- Overhang resulting in a total length beyond 53 feet is not legal without a permit
- Steel pipes, beams, and similar construction materials are not exempt
Width: 8 feet 6 inches
Height: 13 feet 6 inches
Weight: 80,000 pounds gross
- Single axle: 20,000 pounds
- Tandem: 34,000 pounds
- Tridem: 42,000 pounds (with at least 8 feet 1 inch spacing)
ROUTINE PERMIT LIMITS
Length: 120 feet
Width: 18 feet
Height: 18 feet
Weight Limits:
- Single axle: 20,000 pounds
- Tandem: 46,000 pounds
- Tridem: 60,000 pounds
- Quad: 80,000 pounds
Steer Axle: Weight is based on the tire’s rating (as printed on the sidewall), multiplied by two. The vehicle must be licensed for the total weight being permitted.
Loads exceeding these dimensions or weights are classified as super loads.
ESCORT REQUIREMENTS
Length:
- Over 85 feet: 1 escort or amber revolving light
- Over 120 feet: 1 escort required
- Overhang:
- Front projection over 25 feet
- Rear projection over 10 feet
- Requires 1 escort or amber revolving/strobe light on the rear of the load
Height:
- Over 14 feet 6 inches: 1 escort with high pole
Width on 4-Lane Roads:
- 14 feet 6 inches to 16 feet 6 inches:
- 1 rear escort or 2 amber/strobe lights (one on power unit, one at the rear of the load)
- Over 16 feet 6 inches: 1 escort
Width on 2-Lane Roads:
- Width over half the roadway up to 14 feet 6 inches: 1 front escort
- Over 14 feet 6 inches: 1 escort
- For loads up to 14 feet 6 inches wide that exceed half the roadway, escorts can be replaced with amber/strobe lights if lane width is 12 feet or more and shoulders are adequate
MISCELLANEOUS
Attachments like blades, buckets, and counterweights do not need to be removed if the load is only overdimensional. If the load is overweight, these items must be hauled separately.
SIGNS, FLAGS & LIGHTING
- “Oversize Load” signs and red flags are required when the load exceeds 75 feet in length, 8 feet 6 inches in width, or 14 feet 4 inches in height
- Flags are required on any rear overhang over 4 feet
- Flag placement:
- Each front corner of the towing unit
- Each rear corner of the load
- At widest points or protrusions
- Amber revolving light (minimum 7 inches tall and 7 inches wide) is required on the towing unit when:
- Length exceeds 85 feet
- Front overhang exceeds 25 feet
- Rear overhang exceeds 10 feet (light should be placed on the rear of the load)
- Gross weight exceeds 80,000 pounds
- An escort may be used instead of the amber light in applicable cases
