Brief Description: Restricting the use of compression brakes.

Sponsors: By Representatives Fromhold, Moeller, Murray, Hunter and Jarrett.

House Committee on Transportation
Senate Committee on Transportation

Background:

An engine compression brake device (compression brake) is an engine component that operates by opening the exhaust valve at the top of the compression stroke when the engine is in braking mode. The opening of the exhaust valve results in the discharge of compressed air, which creates a characteristic sound. Installing compression brakes in a vehicle provides supplemental braking capacity, allowing for greater control over the vehicle's speed and increased life for the vehicle service brakes.

Washington law does not regulate the use of compression brakes. However, certain local jurisdictions have ordinances that regulate their use.

Federal law regulates the noise levels generated by new trucks at the time they are delivered to the customer.

Summary:

A motor vehicle with a declared gross weight greater than 10,000 pounds operating on public roads is subject to new requirements if the vehicle is equipped with compression brakes. These brakes are defined as a device that uses the engine and transmission to impede the forward motion of the motor vehicle by compression of the engine.

The driver of a vehicle equipped with compression brakes may not use the device unless the vehicle also contains an operational muffler and exhaust system. This system must maintain the noise level at 83 decibels or less for vehicles manufactured after January 1, 1979, and 80 decibels or less for vehicles manufactured after January 1, 1988.

If a vehicle does not contain a muffler and exhaust system that meets these standards, the driver may still use compression brakes if the driver reasonably believes that an emergency exists that requires the use of the device to:

• protect against an immediate threat to the physical safety of the driver or others;
• protect against an immediate threat to property; or
• reduce the speed of the vehicle on a downhill grade.

A person violating these requirements is subject to a $250 monetary penalty for the first violation, a $500 monetary penalty for the second violation, and a $750 monetary penalty for each subsequent violation.

Local jurisdictions are allowed to adopt more restrictive ordinances regarding the use of compression brakes.

The Washington State Patrol must adopt rules for law enforcement agencies to enforce these requirements.

Votes on Final Passage:

House   88   10
Senate   41   6   (Senate amended)
House   87   9   (House concurred)

Effective: July 24, 2005