Ideally, in the event of a breakdown on a motorway you would drive your car to the next available exit and then find a safe place to park up. If this isn't possible, drive onto the hard shoulder and close to the barrier or verge so that you can safely leave your car. Leave your side lights and hazard lights on and make sure everyone gets out safely on the left hand side of the car and go behind the barrier or up onto the verge. It is dangerous to sit inside the car on the side of a motorway.
Call your breakdown service straight away, either from your mobile phone or from one of the emergency phones located by the road. Mobile phone apps that alert your breakdown service to your location are also available. Do not attempt to fix the fault yourself and never attempt to cross the carriageway, no matter how quiet the road might appear.