Every vehicle or combination of vehicles using compressed air at the wheels for applying the service brakes shall be equipped with an emergency stopping system meeting the requirements of this section and capable of stopping the vehicle or combination of vehicles in the event of failure in the service brake air system as follows:

a. Towing vehicles which use compressed air at the wheels for applying the service brakes shall be equipped with a device with an automatic means of actuating an emergency stopping system on the towed vehicle. The device shall operate automatically in the event of a reduction of the service air brake supply of the towing vehicle to a fixed pressure which shall not be lower than 20 pounds per square inch nor higher than 45 pounds per square inch.

b. Towed vehicles shall be deemed to be in compliance with this section when:

(1) The towed vehicle is equipped with a no-bleed-back relay-emergency valve or equivalent device, so designed that the supply reservoir used to provide air for the brakes is safeguarded against backflow of air from the reservoir through the supply line; and

(2) The combination of vehicles is capable of stopping within the distance and under the conditions specified in subsections g. and h. of this section.

c. If the service brake system and the emergency stopping system are connected in any way, they shall be so constructed that a failure or malfunction in any one part of either system, including brake chamber diaphragm failure but not including failure in the drums, brakeshoes, or other mechanical parts of the wheel brake assemblies, shall not leave the vehicle without one operative stopping system capable of complying with the performance requirements in subsection g. of this section.

d. No vehicle or combination of vehicles upon failure of the service brake air system shall be driven on a highway under its own power except to the extent necessary to move the vehicles off the roadway to the nearest place of safety.

e. No vehicle or combination of vehicles shall be equipped with an emergency stopping system that creates a hazard on the highway, or increases the service brake stopping distance of a vehicle or combination of vehicles, or interferes in any way with the application of the service brakes on any vehicle or combination of vehicles.

f. Any energy-storing device which is a part of the emergency stopping system shall be designed so that it is recharged or reset from the source of compressed air or other energy produced by the vehicle, except that energy to release the emergency stopping system may be produced by the driver’s muscular effort from the driver’s seat. No device shall be used which can be set to prevent automatic delivery of air to protected air supply reservoirs of motor vehicle emergency stopping systems when air is available in the service brake air supply system.

g. Every motor vehicle or combination of vehicles, at all times and under all conditions of loading, upon application of the emergency stopping system, shall be capable of stopping from a speed of 20 miles per hour in not more than the distance tabulated herein for its classification, this distance to be measured from the point at which movement of the emergency stopping system control begins.

EMERGENCY STOPPING SYSTEM REQUIREMENTS

Classification of vehicle Stopping Distance
and combination of vehicles In Feet

A. Passenger-carrying vehicles.

(1) Vehicles with a seating capacity
of 10 persons or less, including
driver, and built on a passenger
car chassis …………… 54

(2) Vehicles with a seating capacity
of more than 10 persons, includ-
ing driver, and built on a passenger
car chassis; vehicles built
on a truck or bus chassis and
having a manufacturer’s Gross
Vehicle Weight Rating of 10,000
pounds or less ………….. 66

(3) All other passenger-carrying vehicles ……. 85

B. Property-carrying vehicles.
(1) Single unit vehicles having a
manufacturer’s Gross Vehicle
Weight Rating of 10,000 pounds
or less …….. 66

(2) Single unit vehicles having a
manufacturer’s Gross Vehicle
Weight Rating of more than
10,000 pounds, except truck trac-
tors. Combinations of a 2-axle
towing vehicle and trailer hav-
ing a Gross Vehicle Weight
Rating of 3,000 pounds or less.
All combinations of 2 or less
vehicles in driveaway or towaway
operation …………… 85

(3) All other property-carrying vehicles
and combination of property-
carrying vehicles …………. 90

h. Tests of deceleration and stopping distance shall be made on a substantially level dry, smooth, hard surface that is free from loose material and where the grade does not exceed plus or minus 1%. No test of emergency stopping system performance shall be made upon a highway at a speed in excess of 25 miles per hour.

i. The provisions of this section shall not apply to:

(1) Auxiliary dollies, special mobile equipment, or special construction equipment; or

(2) Disabled vehicles when being towed.

j. Every owner or lessee shall instruct and require that the driver be thoroughly familiar with the requirements of this section.

The driver of a vehicle or combination of vehicles required to comply with the requirements of this section shall be able to demonstrate the application and release of the emergency system on the vehicle and each vehicle in combination.

L. 1987, c. 402, s. 2.