When you are passed your test it is advisable to take Pass Plus course which will include motorway driving. When first driving on a motorway it can be very intimidating, so taking a few more lessons on motorway driving with an instructor is advisable.
When about to join a motorway you will be on a slip road, which is called an acceleration lane. The idea is to build up your speed so that you join the motorway at about the same speed as existing traffic. Too slow a speed when merging with motorway traffic could cause, at the very least, vehicles having to brake and change direction and, in short, is extremely dangerous. When joining the motorway, your MSPSL routine is absolutely vital.
Most motorways have three lanes. Contrary to belief, there is no such thing as a fast lane. Each lane has the same speed limit of 70 m.p.h. You should drive in the left hand lane except when overtaking, when you can use lanes 2 or 3. In lane 2 you can overtake a succession of slower moving vehicles in lane 1 and in fact stay in lane 2 if you are making progress, i.e. you are overtaking vehicles in lane 1 albeit slowly. The only time you would go into lane 3 would be to overtake, but you should move back into lanes 2 and 1 after each overtaking manoeuvre. When overtaking, you may also need a cursory blind spot check.
When driving on a motorway you should always keep a safe distance from the vehicle in front of you. This can be achieved by using the 2 second rule. What this means is as the vehicle in front of you passes a fixed object such as a road sign or bridge, you should be able to count to yourself “one thousand, two thousand” before reaching that point. If you cannot, you are travelling too close and should drop back. If you are driving in rain, you would need to double the distance and in the case of ice and snow it could be up to ten times the distance.
If you are travelling in lane 1 on very busy motorways and your lane traffic is moving quicker than that in lanes 2 and 3, you may still go past them. Because of the flow of traffic this is not regarded as undertaking. Only in the event of a breakdown may you use the hard shoulder to stop and it is always advisable to get out of your car via the passenger door and stand on the other side of the metal barrier for safety.
When leaving the motorway, you need to look well ahead, plan and look for road signs for your exit. Because of the higher speed you will need to get into the correct lane in plenty of time. If you leave it too late, you may not be able to get into the correct lane because of the weight of traffic. Before reaching your exit, you will see count down posts by the side of the road, showing 3 bars, 2 bars and 1 bar. You should put your left signal on after the 3 bar post but before the 2 bar post. One you have left the motorway you will be on a deceleration lane where you should reduce your speed to match the speed of the new road.