Highway Code Rule 272
Unless signs indicate that a lane leads directly off the motorway, you will normally leave the motorway by a slip road on your left. You should
- watch for the signs letting you know you are getting near your exit
 - move into the left-hand lane well before reaching your exit
 - signal left in good time and reduce your speed on the slip road as necessary.
 
Section: Motorways (rules 253 to 273)
Subsection: Leaving the motorway (rules 272 to 273)
                            Highway Code Rule 273
On leaving the motorway or using a link road between motorways, your speed may be higher than you realise – 50 mph may feel like 30 mph. Check your speedometer and adjust your speed accordingly. Some slip-roads and link roads have sharp bends, so you will need to slow down.
Section: Motorways (rules 253 to 273)
Subsection: Leaving the motorway (rules 272 to 273)