Illinois Oversize Permits

Legal size/weight limits, escort thresholds, travel restrictions, and permit office contact for Illinois.

⚠ REFERENCE ONLY — NOT A PERMIT. VERIFY WITH THE STATE BEFORE YOU TRAVEL.

These figures are a reference summary of publicly published state rules, not a substitute for a state-issued permit and not legal advice. Rules change — always confirm current limits and requirements directly with the state permit office before you plan or run a move. Last verified: 2026-07-16. Oversize Ops is NOT responsible and CANNOT be held liable for decisions made from this reference. Official source ↗

Legal Maximum Dimensions (no permit required)

Width: 8.5ft (102in)
Height: 13.5ft (162in)
Max semitrailer length: 53ft
Max overall combination length: 65ft
Max kingpin to rear axle: 45.5ft
Gross Weight: 80,000 lbs
Single Axle: 20,000 lbs
Tandem Axle: 34,000 lbs

625 ILCS 5/15-103: the height of a vehicle from the underside of the tire to the top of the vehicle, inclusive of load, shall not exceed 13 ft 6 in (162 in) on any highway in the State. Penalty per 625 ILCS 5/15-113(b).

Official source for this height limit →

625 ILCS 5/15-107: 53 ft semitrailer on Class I and Class II highways, with no overall limit there. On NON-designated highways the whole combination is capped at 65 ft, which a tractor plus a 53 ft trailer will typically exceed — so the trailer being legal does not make the rig legal. Kingpin-to-rear-axle max 45 ft 6 in for trailers over 48 ft.

Kingpin to rear axle max 45 ft 6 in for trailers over 48 ft — more permissive than most states.

Official source for these length limits →

Escort / Pilot Car Thresholds (see glossary for terms, certification requirements for the driver)

Front escort required over: 14.5ft wide
Rear escort required over: 14.5ft wide
Both escorts required over: 16ft wide
Height escort required over: 14.5ft tall

Per IDOT Form OPER 993 (Provision B): ONE civilian escort if load exceeds 14'6" wide (174 in), 14'6" high (174 in), or 110' long. TWO civilian escorts (one front, one rear) if it exceeds two or more of those three thresholds. THREE civilian escorts if over 16' wide (192 in), 18' high (216 in), or 145' long. Illinois State Police escort required if over 18' wide (216 in), 18' high (216 in), or 200' long, or when a bridge/district analysis requires it. Lead escort must carry a height pole for loads over 14'6" high. Not tied to weight.

Travel Restrictions

Night travel: Generally allowed
Weekend travel: Generally allowed
Sunday travel: Generally allowed

Per OPER 993 authorized times: overweight-only (legal-dimension) loads 24/7. Loads <=12' wide/13'6" high/200' long: 24/7 but require one extra civilian escort during hours of darkness. Loads <=14'6" wide/15' high/200' long: daylight, 7 days/week. Loads <=16' wide/17' high: daylight Mon-Fri + Saturday until noon. Loads >200' long: daylight Mon-Fri only, no Sat/Sun. Loads >16' wide or >17' high: 9 a.m.-3 p.m. Mon-Fri only. Cook County expressways prohibit loads over 12' wide, 13'6" high, or 120,000 lbs (with listed interstate exceptions). In 9 named counties loads over 14'6"-16' wide are limited to 9 a.m.-3 p.m. Mon-Fri. City of Chicago CBD has separate city-issued time rules.

Holiday blackouts: No permit travel on New Year's Day, Memorial Day, Independence Day (July 4), Labor Day, Thanksgiving, and Christmas; exact blackout dates/times posted under Holiday Permit Travel Restrictions on the ITAP home page.

See how Illinois compares to every state ›

Superload Thresholds

Width over: 16ft
Length over: 150ft
Weight over: 200,000 lbs

OPER 993 does not state a single numeric superload threshold. IDOT processes as superloads any load requiring structural/bridge analysis, and any towed load that fails minimum axle-spacing requirements. ISP-escort thresholds (over 18' wide, 18' high, or 200' long) mark the upper boundary. Precise numeric superload definition lives in the IDOT OSOW Policy Book.

Estimated Permit Cost Verify before relying

Fee-table structure confirmed in law, but the actual dollar tables were not retrievable as readable text

Source: 625 ILCS 5/15-301, 92 Ill. Admin. Code Part 554/2520 — verify current fee with the permit office before budgeting a move.

Permit fee only — does not include escort/pilot-car service costs (market-rate, arranged separately) or third-party permit-service fees. This is an estimate for planning purposes, not a quote.

Get a Permit

Online portal: https://webapps.dot.illinois.gov/ITAP/
Phone: 217-785-1477

Chicago metro area restrictions on I-90/94 and other interstates. Posted bridge weights common.

Planning a move through Illinois?

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