General (rules 253 to 254)
Prohibited vehicles. Motorways MUST NOT be used by pedestrians, holders of provisional motorcycle or car licences, riders of motorcycles under 50 cc, cyclists, horse riders, certain slow-moving vehicles and those carrying oversized loads (except by special permission), agricultural vehicles, and powered wheelchairs/powered mobility scooters (see Rules 36 to 46 inclusive).
From 4 June 2018 provisional licence holders may drive on the motorway if they are accompanied by an approved driving instructor and are driving a car displaying red L plates (D plates in Wales), that’s fitted with dual controls.
Laws HA 1980 sects 16, 17 & sched 4, MT(E&W)R regs 3(d), 4 & 11, MT(E&W)(A)R, R(S)A sects 7, 8 & sched 3, RTRA sects 17(2) & (3), & MT(S)R reg 10
Traffic on motorways usually travels faster than on other roads, so you have less time to react. It is especially important to use your mirrors earlier and look much further ahead than you would on other roads.