What Car? Q&A - Who has right of way on the motorway?

Q: I am fed up of being stuck on motorways behind drivers who slam on their brakes at every slip road. They seem to be slowing in order to allow drivers joining the motorway to do so in front of them. Surely this is wrong, what are the rules regarding slip roads?
A Llewellyn

A: First of all, vehicles already using the motorway have the right of way. So drivers on the motorway really shouldn’t be braking as they approach slip roads. In fact it can be dangerous to do so.

Ideally, if you are travelling in lane one and can see vehicles on the slip road you should, if possible, move into a lane on your right, allowing traffic to join the motorway safely and at an appropriate speed.

However, do not move into a lane to your right if it forces existing motorway users to change their speed or position. Ultimately, it is the vehicle joining the motorway that should give way.

The Highway Code says that traffic joining the motorway should:
· Give priority to traffic already on the motorway
· Adjust speed to fit safely into the traffic flow in the left-hand lane
· Never cross solid white lines