You can join a motorway
At an entry point where a slip road leads to the motorway, adjust your speed to that of the traffic already on the motorway before joining it. Give priority to traffic already on the motorway.
Join where there’s a suitable gap in the left-hand lane. Use the Mirrors – Signal – Manoeuvre/Position – Speed – Look (MSM/PSL) routine.
A quick sideways glance might be necessary to verify the position of other vehicles. Try to avoid stopping at the end of the slip road unless queuing to join other slow-moving traffic.
At some slip roads there’s no need to join by merging because the joining lane may continue as a dedicated lane. Signs and road markings normally indicate this arrangement.
Once you’ve joined the motorway, keep in the left-hand lane until you’ve had time to judge and adjust to the speed of the traffic already on the motorway.
In some cases, the lane merges from the right. Take extra care when joining or meeting traffic at these locations.