---
title: Illinois Oversize & Overweight Permits (OS/OW) | IDOT Superload | Alpine Truck Service
description: Expedited Illinois IDOT oversize permits, Chicago curfew management, Illinois Tollway clearances, and ISP escorts across I-80, I-55, and I-90. Call (918) 607-6547.
image: https://www.alpinetruckservice.com/alpine-third-party-charges.webp
---

# Illinois Oversize, Overweight & Superload Permitting Services

Comprehensive commercial trucking permits and heavy haul compliance across Illinois.

## Agency & Permitting Authority
- **Agency**: Illinois Department of Transportation (IDOT)
- **Portal**: IDOT Automated Permit System (ITAP)
- **Regulatory Advisory**: State DOT regulations and permit processing queues are determined by individual state transportation authorities and vary by agency workload. Carriers should verify active route advisories and state requirements prior to movement.

## Legal vs. Routine Permitted Dimensions
- **Legal Width**: 8' 6" (8' 0" on non-designated Class III highways) | **Max Routine**: 14' 6"
- **Legal Height**: 13' 6" | **Max Routine**: 15' 0"
- **Legal Length**: 53' Semi-Trailer / 65' Overall | **Max Routine**: 145' 0"
- **Legal Gross Weight**: 80,000 lbs | **Max Routine**: 120,000 lbs
- **Axle Limits**: Single: 20,000 lbs, Tandem: 34,000 lbs, Tridem: 42,000 lbs

## Permitting Scope & Services in Illinois
- **Routine Oversize (OS) Cab-Cards**: Single-trip authorizations for dimensions exceeding 8' 6" (8' 0" on non-designated Class III highways) width or 13' 6" height.
- **Overweight (OW) Axle Permits**: Overload cab-cards for heavy machinery and configurations exceeding 80,000 lbs GVW.
- **Multi-Axle Superload Permits**: Specialized filings exceeding Over 120,000, including State DOT and certified partner bridge reviews, route surveys, and police escorts.
- **Annual & Blanket Fleet Permits**: Continuous-operation annual highway authorizations for construction fleets.
- **Temporary Trip & Fuel Permits**: 72-hour IRP vehicle registration and IFTA fuel tax credentials.
- **County, City & Toll Road Clearances**: Municipal authorizations and turnpike clearances.

## Superload Permitting & State Review Protocol
- **Weight Trigger**: Over 120,000 lbs GVW or exceeding IDOT standard axle weight charts
- **Width Trigger**: Over 14' 6" wide
- **Height Trigger**: Over 15' 0" high
- **Length Trigger**: Over 145' 0" overall length
- **State & Partner Bridge Review**: Illinois Department of Transportation (IDOT) electronic systems and certified structural engineering partners evaluate axle load distribution across bridge structures upon submission.
- **Route Surveys & Clearances**: Required for extreme heights/widths to verify overhead physical clearances.
- **Utility & Escorts**: Coordinated wire lifts with power utilities and State Police / Highway Patrol escorts.

## Pilot Cars & Escort Vehicle Requirements
- **Front Escort**: Required over 14' 6" wide on two-lane roads; or height over 14' 6" (with height pole)
- **Rear Escort**: Required over 14' 6" wide on all highways; length over 100' 0"; rear overhang over 10' 0"
- **Height Pole**: Required for loads exceeding 14' 6" in height (lead vehicle with calibrated pole)
- **Police Escort**: Illinois State Police (ISP) District escort required over 16' 0" wide, 16' 0" high, 145' 0" long, or over 200,000 lbs

## Metro Curfews & Travel Restrictions
- **Curfew Zones**:
  - Cook County / Chicago Metro Area (I-90, I-94, I-290, I-55, I-294): 6:00–9:00 AM & 4:00–6:00 PM M-F (loads over 10' wide or 13'6" high)
  - East St. Louis Metro (I-55, I-64, I-70, I-270): 6:30–9:00 AM & 4:00–6:00 PM M-F
- **Travel Rules**: Daylight only (1/2 hour before sunrise to 1/2 hour after sunset) Monday through Friday. Saturday travel allowed until 12:00 noon for loads under 12' wide. No Sunday travel. Routine overweight-only loads may travel 24/7.

## Key Freight Corridors
- I-80 (Transcontinental Freight Arterial)
- I-55 (Chicago to St. Louis)
- I-90 / I-94 (Chicago Logistics Spine)
- I-57 (Central/Southern IL Spine)
- I-70
- Illinois Tollway System (I-294, I-88, I-355)

## Frequently Asked Questions
### How long does IDOT take to process an Illinois oversize permit?
Routine single-trip permits submitted via ITAP are typically processed in 2–4 business hours. Superloads requiring IDOT bridge engineering analysis take 3–7 business days.

### Do I need a separate permit for the Illinois Tollway?
Yes. The Illinois State Toll Highway Authority (ISTHA) requires its own permit for travel on I-294, I-90 Tollway, I-88, and I-355, in addition to the IDOT state permit.

### What are the Chicago rush hour curfew hours for oversize loads?
In Cook County and Chicago, loads over 10' wide or exceeding legal height cannot travel between 6:00–9:00 AM and 4:00–6:00 PM on weekdays.

### What is Illinois's superload weight threshold?
Shipments over 120,000 lbs gross weight, 14'6" wide, 15'0" high, or 145' long are classified as superloads, requiring structural bridge calculations and State Police escorts.

## Contact & Direct Dispatch
- **Direct Phone**: (918) 607-6547 (CALL: [918-607-6547](tel:9186076547))
- **Email**: [permits@alpinetruck.com](mailto:permits@alpinetruck.com)
- **Online Intake**: [alpinetruckservice.com/permits/illinois](https://www.alpinetruckservice.com/permits/illinois)