Drivers could land themselves with a hefty fine and a ban from driving for undertaking on the motorway.
The Highway Code states that drivers should not overtake when moving over to the left hand lane.
While the act of undertaking is not illegal in itself, it could fall under a dangerous driving offence, according to the RAC.
This could lead to a harsh penalty of up to nine points or a disqualification, a fine of up to £5,000 and a court summons.
In most circumstances, undertaking could lead to a careless driving offence - which is a lesser punishment of three points on the licence and a £100 fine.
But there are some circumstances in which it is okay to use the left hand lane to undertake drivers on motorways and dual carriageways.
One example the Highway Code refers to is when traffic on the left is moving faster than the right during “congested conditions”.
The main problems lie when drivers decide to weave in and out of lanes in order to overtake other drivers.
Rule 268 of the Highway Code says: “Do not overtake on the left or move to a lane on your left to overtake.
“In congested conditions, where adjacent lanes or traffic are moving at similar speeds, traffic in left-hand lanes may sometimes be moving faster than traffic to the right in your lane even if this means passing traffic in the lane to your right.
“Do not weave in an out of lanes to overtake.”
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