COVID-19: The DVSA approved the resumption of driving lessons in England and Wales from 12 April and new customers can book lessons now. We’ve taken steps to ensure your safety.

Book Online
Drive with Red

The Highway Code – What Does it Say About Undertaking?

Ever seen a driver speed down the inside of another car on the motorway, frustrated because the driver in the middle lane is ‘going too slow!’, or ‘won’t get over’? 

Unfortunately, this is a much more common sight on UK motorways than we’d hope for.

Undertaking can easily cause accidents, as when drivers pull in they may miss other driver undertaking, approaching them in their blind spot. 

What is undertaking?

‘Undertaking’ is when one vehicle passes another slower moving vehicle on the left-hand side.

Is undertaking illegal? 

You may have heard that undertaking in the UK is illegal, however this is not the case. 

It is advised in the Highway Code that drivers should only overtake on the right, though this is not a legal requirement. There are however certain conditions where it may be safe to undertake on the left hand side, such as in slow-moving traffic. 

Undertaking can be very dangerous, especially at high speeds on the motorway. A driver may not have sufficient time to conduct adequate mirror check and safely pull in if another driver is approaching more quickly in their inside lane. 

tailgating on a three-lane autobahn

So what does the Highway Code have to say?

Rule 267 in The Highway Code states:

only overtake on the right’

This is a matter of safety – undertaking on the left hand side is dangerous as it’s harder for drivers to spot approaching cars. However, this is advisory and not a legal requirement, as there are situations when undertaking is accepted, as explained in rule 268. 

Rule 268 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.’.

However you MUST not use the hard shoulder to overtake as per rule 269 of the highway code. Doing so will likely result in a FPN and a £100 fine.

RED’s advice on undertaking 

Whilst undertaking isn’t illegal per se, it can be extremely dangerous to do so, and if you’re caught undertaking another driver you could be in for a penalty under another section of the Highway Code – dangerous driving. This could land with you with a FPN and a £100 fine or worse, depending on the severity of the offence. 

If you find yourself needing to undertake, for example in slow moving traffic where you’re moving at similar speeds, be aware that the driver ahead may not be checking their inside mirror and/or blind spots before pulling in, so proceed slowly and with caution. 

Like with many situations when driving, you’ll need to lean on your previous experience to judge whether it’s safe to conduct this manoeuvre 

If you’re caught weaving in and out of lanes and driving erratically then you could end up with an FPN on your hands!  

You might also be interested in…

Man riding bicycle in cycle lane


Confused how to safely overtake cyclists? Find out what the Highway Code has to say.

Road sign showing directions to Ring Road from a roundabout


Been on a few lessons and struggling with roundabouts? Find out how the Highway Code says to tackle them and you’ll be well on your way to passing your test!

Driving instructor and learner in car

The 10 most common reasons for failing your test

Here at RED Driving School we want to ensure you pass your driving test with minimum fuss and hassle. With Independent Driving introduced to the practical driving test today, it’s important you still remember the fundamental things you should and shouldn’t be doing on your driving lessons and driving test!