Motorway driving – a skill that’s hard to come by

In the first paragraph learners are allowed on the Motorway, in the second they are not. What is the law concerning this? I think it should be part of learning to drive. Most congestion, frustration and, subsequently, anger, is caused by people sitting in the wrong lane. The simple rule of ‘keep left unless you’re overtaking’ should be enforced religiously. It would solve a lot of problems and should be drilled into young drivers at the earliest opportunity. Motorways would then be a less daunting prospect and the need for tailgating/flashing/undertaking would be removed.