Speed limiting technology looks set to become mandatory for all vehicles sold in Europe from 2022, after new rules were provisionally agreed by the EU.
The Department for Transport said the system would also apply in the UK, despite Brexit.
Campaigners welcomed the move, saying it would save thousands of lives.
Road safety charity Brake called it a "landmark day", but the AA said "a little speed" helped with overtaking or joining motorways.
Safety measures approved by the European Commission included intelligent speed assistance (ISA), advanced emergency braking and lane-keeping technology.
The EU says the plan could help avoid 140,000 serious injuries by 2038 and aims ultimately to cut road deaths to zero by 2050