Heavy Vehicle (Vehicle Standards) National Regulation

The braking system of a heavy motor vehicle built after 1930 or a heavy combination that includes a heavy motor vehicle built after 1930 must, on application of a brake, be able to produce the performance mentioned in subsections (2) to (4)—

when the vehicle is on a dry, smooth, level road surface, free from loose material; and

whether or not the vehicle has goods or passengers in it; and

whether or not the vehicle is used alone or as part of a combination; and

without part of the vehicle moving outside a straight path—

centred on the longitudinal axis of the vehicle before the brake was applied; and

3.7m wide.

The braking system of a heavy motor vehicle or heavy combination that includes a heavy motor vehicle built after 1930 must bring the vehicle from a speed of 35km/h to a stop within—

16.5m when the service brake is applied; and

40.5m when the emergency brake is applied.

The braking system of a heavy motor vehicle or heavy combination that includes a heavy motor vehicle built after 1930 must decelerate the vehicle, from any speed at which the vehicle can travel, by an average of at least—

2.8m a second a second when the service brake is applied; and

1.1m a second a second when the emergency brake is applied.

The braking system of a heavy motor vehicle or heavy combination that includes a heavy motor vehicle built after 1930 must achieve a peak deceleration of the vehicle, from any speed at which the vehicle can travel, of at least—

4.4m a second a second when the service brake is applied; and

1.5m a second a second when the emergency brake is applied.

The parking brake of a heavy motor vehicle or heavy combination must be able to keep the vehicle, or any combination of which it is a part, stationary on a 12% gradient—

when the vehicle or combination is on a dry, smooth road surface, free from loose material; and

whether or not the vehicle or combination has goods or passengers in it.