Oversize Load Permits Explained: A Practical Guide for Equipment Shippers

The Federal Baseline: What the Government Actually Controls

Here's a common misconception: there is no federal oversize permit. The federal government sets baseline legal limits for the National Network (Interstate highways and designated federal-aid routes), but it does not issue permits. Those come from individual states.

Federal baseline limits on the National Network:

• Width: 102 inches (8 feet 6 inches)
• Gross Vehicle Weight (GVW): 80,000 lbs
• Single axle weight: 20,000 lbs
• Tandem axle weight: 34,000 lbs
• Height: No federal limit — this is entirely state-controlled

Any load exceeding these thresholds on the National Network requires a permit from each state the load travels through. On non-Interstate routes, state and local limits may be even more restrictive.

How State Permits Work

Each state has its own Department of Transportation (or equivalent agency) that issues oversize and overweight permits. Permits are load-specific — they specify the exact route, the load dimensions and weight, the dates of travel, and any conditions (escort requirements, travel time restrictions, etc.).

Key points about state permits:

• Every state on the route requires its own permit. A Houston-to-Atlanta move crossing Texas, Louisiana, Mississippi, Alabama, and Georgia requires five separate permits.
• Permits are nondivisible load permits. States generally only issue permits for loads that cannot be broken down into smaller pieces without significant effort or damage to the load's integrity. Equipment qualifies as nondivisible.
• Permit fees vary widely. A single-state permit might cost $15–$50 for a standard oversize load. Multi-state packages for complex routes can run $400–$1,500+.
• Processing times vary. Standard oversize permits often process in 1–3 business days. Superloads requiring engineering review can take 2–6 weeks.

Permit Tiers: Standard Oversize vs. Superload

Most states recognize two broad tiers of oversize loads:

Standard Oversize: Loads that exceed legal limits but fall within the state's "routine" permit thresholds. These are processed quickly (often same-day or next-day) and don't require engineering review. Typical thresholds: up to 14–16 feet wide, up to 14.5–15 feet tall, up to 120,000–150,000 lbs GVW (varies by state).

Superload: Loads that exceed the state's routine permit thresholds. These require engineering review of bridge capacities along the proposed route, pre-run route surveys, and sometimes law enforcement escort. Common superload triggers: over 150,000 lbs GVW, over 16 feet wide, or over 15 feet tall. Processing times: 2–6 weeks. Some states require the shipper to pay for bridge engineering studies.

Escort Vehicle (Pilot Car) Requirements

Escort vehicles — also called pilot cars — are required when a load exceeds certain dimension thresholds. Requirements vary by state, but common triggers include:

• Width over 12 feet: Front escort typically required
• Width over 14 feet: Front and rear escorts typically required
• Width over 16 feet: Law enforcement escort often required in addition to civilian escorts
• Height over 14.5 feet: Height pole vehicle required in some states to check clearances

Escort vehicles must be equipped with specific lighting, signage, and communication equipment per state requirements. Escort drivers must be certified in most states. IronHaul coordinates all escort vehicles as part of the permit package.

Travel Time Restrictions

Most states impose travel time restrictions on oversize loads:

• Daylight-only travel (typically 30 minutes before sunrise to 30 minutes after sunset)
• No travel on Sundays or holidays in some states
• No travel during peak traffic hours in urban areas
• Superloads may be restricted to weekday travel only

These restrictions affect transit time calculations. A 3-day transit on a standard load might take 4–5 days for a superload due to restricted travel windows.

What IronHaul Handles for You

IronHaul manages the entire permit process in-house. When you book a shipment, we determine the permit requirements based on your load dimensions and route, pull all state permits, coordinate escort vehicles, and build a travel plan that complies with all state restrictions. You don't need to know the permit rules for every state — that's our job.

Ready to move your equipment? Call (208) 495-2260, email [email protected], or submit a quote request online. Provide your equipment dimensions and route and we'll handle the rest.