Common motorway blunder which will leave you with £100 fine

An all-too-common motorway manouvre will leave you with a £100 fine, drivers have been warned. Nobody likes middle-lane hoggers - but if you take it upon yourself to undertake them, it'll hit you in the pocket.

"Undertaking" refers to the act of overtaking a slower vehicle on its left-hand side. If you're stuck behind a middle-lane hogger, you might be tempted to undertake, but this could lead to a fixed penalty notice for careless driving or driving without due care and attention. The usual punishment is either three points on your licence or a £100 fine.

More severe undertaking could be deemed dangerous driving, with potential penalties including disqualification, a £5,000 fine, and a court summons. However, there's a loophole that could help you avoid a fine for undertaking on the motorway.

Read more: Drivers warned over 'polite' move

According to the Highway Code, it's acceptable to undertake in slow-moving traffic if your lane is moving faster than the one on the right. In such situations, it's safer to undertake than to zigzag through traffic.

The Code states: "In congested conditions, where adjacent lanes of traffic are moving at similar speeds, traffic in left-hand lanes may sometimes be moving faster than traffic to the right. In these conditions, you may keep up with the traffic in your lane even if this means passing traffic in the lane to your right. Do not weave in and out of lanes to overtake."

Undertaking is also permitted during average speed checks, if signs instruct you to "stay in lane", or when average speed limits are enforced.

A staggering number of drivers are not adhering to a significant rule change that was implemented last year, and they could be hit with a £1,000 fine.