Motorway test?

When driving along on the motorway, it amazes me sometimes that there's no more accidents than there should be.  For example, there we are, towing the caravan in the inside lane, especially in busy traffic, approaching a slip road with oncoming traffic, cannot move into middle lane because there's way to many vehicles, so no where to go, and the idiots on the slip insist on getting on no matter what - don't they know that the little dotted lines they see as they are getting on is meant to "give way" - when learners have passed their test, they should have driving experiene with someone experienced in how to use the motorway properly - there could probably be less accidents