Illinois Tire Regulations

Tire Size, Thread Depth, Width and Snow Chains Regulations

Tire chains of reasonable proportion will be legal when required for safety because of snow, ice or other conditions causing vehicles to skid. Operating condition of pneumatic tires.

(a) Definition. The term “spare tire” as used in this Section 12-405 means any new, used or specially constructed tire that is either carried or installed for short term emergency use.

(b) Promulgated Rules. The Department shall promulgate rules concerning unsafe operating conditions of pneumatic tires. The rules shall be enforced by police officers by visual inspection of tires, including visual comparison with simple measuring scales or gauges. The rules shall include precepts and standards for determining unsafe conditions, including the determination of an effective depth of tread groove, and shall be based upon, to the extent that it is reasonable and practical, all provisions set forth in paragraph (d) of this Section.

(c) Use of Unsafe Tire. 1. No person or organization shall place, drive or move, or cause or allow to be placed, driven or moved, on a highway of this State, any vehicle equipped with one or more pneumatic tires deemed to be unsafe under a provision of paragraph

(d) of this Section or a rule promulgated under paragraph (b) of this Section.

Exemptions. Any restriction stated in this paragraph (c) shall not apply:

• (i) To a tire on a damaged, disabled, abandoned, or other unsafe or unwanted vehicle being legally towed, pushed or otherwise transferred to a repair, relocation, storage, salvage, junking, or other collection site;
• (ii) To a tire on a racing or other competitive vehicle being legally moved or transported, not under its own power, to a lawful competition site or to a bona fide testing site; or
• (iii) To a spare tire either carried or in short term emergency use for only such distance or time as is reasonably necessary to accomplish the repair or replacement of the damaged or unsafe tire for which the spare was substituted.

(e) Criteria for Unsafe Pneumatic Tires. A pneumatic tire shall be deemed to be unsafe if it has:

1. Any part of a ply or cord exposed;
2. A tread or sidewall crack, cut, snag, or other surface interruption deep enough to expose a ply or cord;
3. Any bulge, knot, or separation;
4. Tread wear indicators flush with the tread outer surface in any 2 or more adjacent tread grooves at 3 locations approximately equally spaced around the circumference of the tire;
5. A depth of tread groove less than 2/32 of an inch or less than 1/32 of an inch if on a motorcycle or truckster, measured in any 2 or more adjacent tread grooves at 3 locations approximately equally spaced around the circumference of the tire, at least one of which, in the judgment of the inspecting officer, is a location at which the tread is thinnest, provided that any measurement over a tie bar, tread wear indicator, hump or fillet is excluded;
6. A depth of tread groove less than 4/32 of an inch at any one location and the tire is mounted on the front wheel of a motor vehicle subject to the provisions of Chapter 18B of this Code, provided that any measurement over a tie bar, tread wear indicator, hump or fillet is excluded;
7. A marking which indicates that the tire is not intended for use on a public highway;
8. Been regrooved or recut below the bottom of an original tread groove, except in the case of a special “regroovable” tire that was manufactured or retreaded with thick undertread, identified and regrooved in compliance with the applicable federal standard in Title 49 of the Code of Federal Regulations, and in compliance with each applicable Section of this Code; or
9. Other condition, marking or lack of marking that may be reasonably demonstrated to identify the tire as unsuitable for highway use, including inflation, load, speed or installation condition seriously incompatible with the tire size, construction, or other pertinent marking or feature.

(f) Sale, Lease or Installation of Pneumatic Tires. 1. No person or organization shall sell, lease, or offer for sale or lease, or mount, install, or cause or allow to be mounted or installed, for use on a highway, any pneumatic tire deemed to be unsafe under paragraph (d) of this Section or under a rule promulgated under paragraph (b) of this Section. Except as provided in paragraph (c) of this Section, any person or organization offering a vehicle for sale or lease shall, prior to its being placed, driven or moved on a highway, correct any unsafe tire condition.

No person or organization shall sell, lease, or offer for sale or lease, for highway use, any pneumatic tire, or any vehicle equipped with a pneumatic tire, which has a depth of tread groove less than 3/32 of an inch; except a pneumatic tire on a motorcycle or truckster may have a depth of tire groove of not less than 2/32 of an inch. Groove depth shall not be measured where a tie bar, tread wear indicator, hump or fillet is located.

(g) Compliance and Enforcement. Any police officer, upon reasonable cause to believe that a person or organization has acted or is acting in violation of any provision of this Section, shall require the driver, owner, or other appropriate custodian to submit the tire or tires to an inspection. When so required, the owner or other appropriate custodian shall allow the tire inspection and the driver of a vehicle or combination of vehicles shall stop at a designated location and allow the tire or tires to be inspected or shall move the vehicle or combination to a location that is reasonably convenient and is suitable for such inspection.

Source: http://www.ilga.gov/legislation/ilcs/ilcs4.asp?DocName=062500050HCh%2E+12+Art%2E+V&ActID=1815&ChapterID=49&SeqStart=139700000&SeqEnd=140200000