OOSC, Partie II, Article 12. Pneus a. (9) et b. (4) - Poids dépassant la limite de charge du pneu

The portion of the action item concerning the weighing of the truck was sent to the Size and Weight Committee. There was a question on how to get an accurate weight on single tire, and portable scales such as Haenni were mentioned. A platform scale only gives groupings and cannot get accurate weight on a single tire but a portable scale gives you weights on each wheel end. There was concern on whether wheel end weighing is accurate. Comments that wheel end weighing must be accurate because of weight enforcement.

Comment that you cannot get single tire when there are dual tires on each side. Needs to be applied consistently across the country. There was a question from industry that each jurisdiction has its own weight laws, and how do each state laws apply? A straw poll was taken for jurisdictions on how they conduct weight enforcement, whether enforcement is by the axle or by wheel end? Comment from one jurisdiction that they do it both ways, lowest level they go to is wheel end. Comment that if you don’t go to wheel end, you are not accounting for uneven load. Each jurisdiction indicated that they will go down to wheel end. A comment was made that roadside officials cannot safely break out dual tires by weighing out each tire using plywood. Jurisdiction comment was that they don’t weigh individual tires but multiply the wheel end times 2 and look at total weight of dual to determine if the wheel end is exceeding weight limits on the tire sidewall. Straw poll revealed that most jurisdictions when using portable scales go by wheel end, but when using a platform scale, it would be across the axle.

It was mentioned that OOS criteria should be changed because it says “tire” within the load rating portion, and that is not consistent with how jurisdictions are currently applying the OOS. There was a comment to add a note that "tire" means single tire or a set.

There was concern from industry and commented that a spinning load such as concrete would not be an accurate weight. Spinning load would be legal, then illegal but you can’t stop the spinning in order to get a weight. If it is a constant overweight then it is different than a changing load. Comment and concern from industry that there is no way for drivers to check weight on the wheel end. When it is a reducible load it can be adjusted, but a non-reducible load can be heavy on one side due to the nature of the load. Comment from industry that carrier and driver and static scales cannot determine wheel ends, but only portable scales can determine wheel end. This may lead to drivers being legal when crossing a port of entry static scale, but OOS with a portable unit down the road. Several comments from jurisdictions that it is mostly single tires and problems with suspensions and the overweight on the wheel end is visibly noticeable. A comment from a jurisdiction that not knowing doesn’t negate the fact that it is still overloaded and that it is only being done when it is grossly obvious.

The committee voted to amend the out of service criteria with 3 opposed and no abstentions. Motion passed.

12. Any Tire on Any Front Steering Axle(s) of a Power Unit (a)(9) The weight of a tire on either side of an axle exceeds the tire load limit marked on the sidewall of the tire. This includes overloaded tire resulting from low air pressure. (Load Limit - 393.75(g) or Inflation Pressure - 393.75(i))

12. All Tires Other Than Those Found on the Front Steering Axle(s) of a Powered Unit (b)(4) The weight of a single tire or dual set of tires on either side of an axle exceeds the applicable load limit marked on the sidewall of the tire(s). This includes overloaded tire resulting from low air pressure. (Load Limit - 393.75(g) or Inflation Pressure - 393.75(i)) EXCEPTION: Does not apply to vehicles being operated under the special permit exclusion. (393.75(g)(1))

Issue was reopened on 3/16/2022 for further discussion in Size and Weight Committee due to additional information.

At the time of the request to the Size and Weight Committee there was not a certified scale specifically designed to properly weigh dual tires that was capable of displaying independently display the weight of each tire.

There is now new technology that is able to display individual tire weights on dual tires.

Size and Weight Committee moved the issue back to Vehicle Committee for further discussion in Fall of 2024.

Further Guidance was developed for Operational Policy 14 on how to weigh tires in a dual set and how to document the violation based on what type of scales the inspector has.

The guidance in Operational Policy 14 is as follows:

TIRES

Document each violation separately.

Example: Two flat tires on a wheel end are documented as two violations.

NOTE: When weighing a flat tire, follow scale manufacturer's instructions.

A violation for overloaded sidewall load ratings on tires can only be cited when the sidewall rating(s) is attainable.

When sidewall ratings are attainable, use the following guidance:

On a single tire • Weigh the tire on the wheel end and use the single tire rating on the sidewall. If the weight on the tire exceeds the sidewall load rating for the single tire, document the violation.

On dual tires • When the tires are weighed independently, and the weight on either tire exceeds the sidewall load rating for a dual tire, document the violation once for the wheel end. • When the tires are weighed together as a dual set, and the weight on the dual set of tires exceeds the total of the two sidewall dual tire load ratings combined, document the violation once for the wheel end.

During the discussion with tire manufacturers at S2 at TMC about the issue above, they provided further information that they build a tolerance into the tire above the marked rating. While this guidance varied from roughly 12%-30%, discussion was as to whether that tolerance should be applied to the OOSC. The percentage would have to be less than any of the provided percentages, and precise for enforcement by inspectors for OOSC. The violation would still remain at any amount over the tire weight rating. It was discussed that a 10% over would be appropriate as it was less than any of the percentages provided by the tire manufacturers but would allow for a variation between the violation and OOS condition based on the industry information.

An amendment was voted on for the North American Standard Out-of-Service Criteria Part II, Item 12.a.(9) and b. (4) as follows:

12. TIRES

a. Any Tire on Any Front Steering Axle(s) of a Power Unit (9) The weight on a tire on either side of an axle exceeds the tire load limit marked on the sidewall of the tire by 10% or more. This includes an overloaded tire resulting from low air pressure.

b. All Tires Other Than Those Found on the Front Steering Axle(s) of a Power Unit (6) The weight on a single tire or dual set of tires on either side of an axle exceeds the applicable load limit by 10% or more marked on the sidewall of the tire(s). This includes an overloaded tire resulting from low air pressure.

EXCEPTION: Does not apply to vehicles being operated under the special permit exclusion.