Washington State

House of Representatives

Office of Program Research

BILL

ANALYSIS

Transportation Committee

HB 1486

This analysis was prepared by non-partisan legislative staff for the use of legislative members in their deliberations. This analysis is not a part of the legislation nor does it constitute a statement of legislative intent.

Brief Summary of Bill

Increases the maximum weight limit per tire from 500 pounds per inch of tread to 600 pounds per inch of tread.
Removes the requirement that an axle manufactured after July 31, 1993, carrying more than 10,000 pounds gross weight must be equipped with four or more tires.
Clarifies that the width of a tire is determined by measuring the cross section of the tread of a wheel, the outer face of a track, or the runner of a sled.
Specifies that is is unlawful to have gross weight on a tire in excess of the manufacturer's sidewall rating, or to exceed 600 pounds per inch of tire width.

Background:

The federal regulations that pertain to the performance and safety of truck tires are generally in two categories. First, regulations that affect the testing, certification, and marking of manufactured tires are referred to as the Federal Motor Vehicle Safety Standards, which are administered by the National Highway Safety Administration. Second are the Motor Carrier Safety Standards, which are enforced by the Bureau of Motor Carrier Safety, which is part of the Federal Highway Administration. The Motor Carrier Safety Standards pertain to the application, usage, and condition of the tires. A tire carries up to 11 digits or characters on one sidewall indicating the name of the manufacturer, the producing plant, the tire size, the tire type, load range, sidewall description, and the week and year of production. The width of a tire is one of the factors that is used in determining load ranges.

Presently in Washington, it is not legal to operate any vehicle on the public highways with a gross weight, which includes the load, upon any tire on the surface of the highway in excess of 600 pounds per inch width of the tire. An axle manufactured after July 31, 1993, carrying more than 10,000 pounds gross weight must be equipped with four or more tires. An axle may be equipped with two tires limited to 500 pounds per inch of tire. These provisions do not apply to vehicles operating under oversize or overweight permits or both, while carrying a non-reducible load.

No vehicle or combination of vehicles can operate on the public roadways with a gross load on any single axle in excess of 20,000 pounds, except that two consecutive sets of tandem axles may carry a gross load of 34,000 pounds each, if the overall distance between the first and last axles is 36 feet or more. Other axle combinations are set out in statute based on number of axles and the distance in feet between any group of two or more consecutive axles.

Summary of Bill:

The bill increases the maximum weight limit per tire from 500 pounds per inch of tread to 600 pounds per inch of tread, and removes the requirement that an axle manufactured after July 31, 1993, carrying more than 10,000 pounds gross weight, must be equipped with four or more tires. The bill specifies that it is unlawful to operate a vehicle upon the highway with a gross weight, including load, upon any tire in excess of 10,000 pounds or any axle or tandem axle in excess of the manufacturer's sidewall tire rating, but not to exceed 600 pounds per inch of tire width. The bill clarifies that the width of a tire is determined by measuring the cross section of the tread of a wheel, the outer face of a track, or the runner of a sled.