Review of vehicle horn regulations across various markets towards assessing the minimum sound level of 87 dB(A) under UN R28.

The current UN R28 test procedures specify voltages that cannot be reached by many vehicles’ internal battery charges alone; however, the provisions can be met if the vehicle is warmed up and run at idle. Therefore, OICA proposes to allow vehicles to be run at idle during the test procedure. OICA also proposes to change the minimum sound level requirement for vehicles of category M and N and motorcycles of a power greater than 7 kW from 93 dB to 87 dB.