OOSC, Part II, Item 10. Tires, b. (8) - Dual Tires Worn Less Than 1/32 Inch

In Part II of the North American Standard Out-of-Service Criteria (OOSC), Item 10.b.(8) it states that the OOSC is: So worn that less than 1/32 inch (.8mm) tread remains when measured in any two adjacent major tread grooves (typically any groove containing a tread wear indicator) at 3 separate locations on the tire. There is an interpretation from Peggy Fisher who is now President of the TireStamp Corporation and also Chair of the RP Updates Task Force and former Chair of the TMC Committee Tire & Wheel Study Group from back in 1994 in regards to how far apart measurements should be taken on a tire for the purposes of the Out of Service Criteria. The interpretation was that the measurements should be taken at least 8 inches apart in order to allow for a brake slide or uneven tire wear. I contacted Peggy to see if that interpretation was still accurate. She replied by saying "Even though 15 years have gone by, the opinion stated in the letter you attached is still correct. The measurements should be taken at least 8 inches apart so that the same brake skid area is not measured twice. This distance would be adequate for all over the road tires."

Based on the interpretation and response received from Peggy Fisher, the OOSC Item 10.b.(8) should be amended to address this issue and provide consistency when dealing with tread wear on tires. The "at least 8 inches apart" should be added to the OOSC wording.

Amend the OOSC Item 10.b.(8) to read as follows: So worn that less than 1/32 inch (.8mm) tread remains when measured in any two adjacent major tread grooves (typically any groove containing a tread wear indicator) at 3 separate locations around the tire at least 8 inches apart. (Measurements should not be made on stone ejectors or tread wear indicators).