The braking requirements for all L category vehicles, i.e. mopeds, motorcycles, motorcycles with sidecars, motor tricycles and quadricycles, are specified in United Nations Economic Commission for Europe (UN ECE) Regulation No. 78.03. Whilst this Regulation does not mandate the fitment of anti-lock braking systems to any L category vehicles, it does specify requirements that anti-lock braking systems must comply with if they are fitted. However, it does not specify any requirements concerning the provision of switches to deactivate the anti-lock braking system when the vehicle is being driven off road.
This situation has led to some confusion over whether anti-lock braking system deactivation switches are permitted on L category vehicles or not, especially as the equivalent UN ECE Regulation on braking requirements for M, N and O category vehicles, ECE 13.11, specifically allows the fitment of such deactivation switches under certain circumstances.
To address this situation, the UN ECE Working Party responsible for braking, the Working Party on Brakes and Running Gear (GRRF), developed an 04 series of amendments to ECE 78 to introduce specific requirements covering anti-lock braking system deactivation switches. These new requirements basically specify that, on vehicles that are suitable for off road driving, the anti-lock braking system may be temporarily deactivated for off road driving as long as the following conditions are met:
- Deactivation of the anti-lock braking system can only be initiated when the vehicle is stationary.
- Deactivation of the anti-lock braking system must be initiated by a deliberate action by the rider.
- It must only be possible to deactivate the anti-lock braking system when the vehicle is in "off road" or "all terrain" mode.
- The anti-lock brake system must be automatically reactivated after each start-up of the vehicle.
- Whenever the anti-lock braking system is deactivated, this must be indicated to the rider by a warning lamp.
- It must be possible for the rider to quickly and easily reactivate the anti-lock braking system at any time.
The 04 series of amendments to UN ECE Regulation No. 78 were officially published on 26th July 2017 and, from 1st September 2018, new type approvals to ECE 78 may only be issued to vehicles which comply with the 04 series of amendments.
Additionally, from 1st September 2021, Contracting Parties applying ECE 78 may refuse national or regional type approval to vehicles that do not comply with the 04 series of amendments.