> but it's not possible to safely slow or stop on English motorways.

Bullshit. Never broken down? It's perfectly possibly in the worst possible circumstances to safely pull over to the hard-shoulder.

Smart motorway? The left lane becomes hard shoulder with several miles of lane-closed warnings for other motorists.

Random dual-carriageway with no hard shoulder? Limp-home speed under control is far safe than inattentive driver at motorway speeds. Worst case, stopped in the left (or any!) lane is better than having the driver in the passenger seat.

Jeez!

Feel free to check back in when you pass the driving test.