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Is undertaking illegal on UK roads?
Undertaking is when a vehicle overtakes on the left instead of the right. It is not illegal in the UK, but it can be considered dangerous driving.
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What is Undertaking and is it Illegal?
Undertaking is the practice of passing another vehicle on its left-hand side, rather than on the right. This most commonly happens on motorways and dual carriageways.
In the UK, undertaking is not automatically illegal. However, it can be considered careless or dangerous driving if it is carried out in a manner deemed unsafe or below the standard of a competent and careful driver. In such cases, it may lead to penalties, such as fines and points on your driving licence.
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What is undertaking in driving?
In driving, undertaking refers to passing a slower-moving vehicle on the left, rather than overtaking on the usual right-hand side. As mentioned above, undertaking is not illegal in itself, but it may be treated as careless or dangerous driving and lead to penalties.
Undertaking often occurs when:
- The traffic is heavy or slow-moving.
- A driver unnecessarily remains in the middle or right lane.
- A vehicle ahead is signalling or waiting to turn right.
While undertaking can be safe and permissible in certain circumstances, it is generally discouraged because it can be dangerous. Drivers do not usually expect vehicles to pass on the left and may fail to check their mirrors before changing lanes, increasing the risk of a collision.
What does the Highway Code say about undertaking?
The Highway Code advises that drivers should not undertake on the left or move to the left lane to pass a vehicle (Rule 268), and they should only overtake on the right (Rule 267).
However, the Code allows overtaking in specific situations, such as in slow, congested traffic where the left lane is moving faster, or when the vehicle ahead signals a right turn. You should not weave in and out of traffic and change lanes to undertake.
Although breaching the Highway Code is not a criminal offence in itself, it can be used as evidence in court to establish fault, negligence, or careless driving if an accident occurs.
This means that while undertaking is not explicitly banned, drivers are expected to avoid it unless it is clearly safe and justified by traffic conditions.
Why is undertaking dangerous?
Using the lane on your left to overtake a slower-moving vehicle is considered dangerous, and it increases the risk of collisions and accidents because:
- Drivers do not expect vehicles on the left to move at higher speeds.
- The driver being passed is less likely to check the left mirror before changing lanes.
- Vehicles have larger blind spots and reduced visibility on the left, making it difficult to spot an undertaking car.
- An unexpected undertaking may cause a driver trying to move left to swerve suddenly and lose control of the vehicle.
When is undertaking allowed?
Passing a car or another vehicle on the left is usually considered dangerous, but it may be considered acceptable in certain situations, such as:
- In congested conditions, when adjacent lanes of traffic are moving at similar speeds.
- The car in the lane to your right is waiting to make a right turn or U-turn.
- Road markings or lane directions indicate separate streams of traffic.
- On smart motorways or in average speed check zones.
- When the lane on the left is moving faster than the lane on the right, overtaking on the left is deemed safer than weaving in and out of traffic.
In these situations, the undertaking is unlikely to be seen as careless or dangerous driving. However, if you are at all unsure, you should not engage in undertaking on the left side and only pass a vehicle on the right whenever possible.
When can undertaking a vehicle be considered unlawful?
While not strictly illegal in the UK, undertaking is strongly discouraged, and it can lead to penalties if it is done in a manner that is unsafe or aggressive. You should never pass a vehicle on the left if:
- You are driving at a high speed.
- The road or weather conditions are unsafe.
- The road is winding or narrow.
- There are clear road signs prohibiting undertaking.
- There is a lot of traffic.
- You want to pass a middle lane hogger or get ahead.
- There is a solid white line between the lanes.
- You are on a motorway outside of congested conditions.
Undertaking recklessly can be dangerous, and you can be penalised for doing so.
Can undertaking a vehicle lead to penalties?
Yes, if you are caught undertaking and the police believe that this was careless or dangerous, you could face various penalties, such as:
- A fixed penalty notice for careless driving or driving without due care.
- A £100 fine and a minimum of three points on your driving licence for minor offences.
- Up to 9 penalty points on your licence and a significant fine of up to £5,000 for more serious cases.
- Further sanctions, such as disqualification from driving or a court summons.
Who is at fault if an accident happens while undertaking?
While undertaking is not illegal, it can be used as evidence of careless or dangerous driving if the manoeuvre was unsafe and it led to an accident. Liability for the accident will likely fall on the undertaking driver if they:
- Passed on the left at excessive speed.
- Engaged in undertaking in free-flowing traffic.
- Gave the other driver little time to react.
- Weaved between lanes aggressively.
However, liability for the accident may be shared between the two drivers if the driver being overtaken:
- Changed lanes without checking their mirrors and blind spots properly.
- Failed to signal before moving left.
- Was unnecessarily hogging the middle or right lane.
Undertaking is not automatically illegal in the UK, but it can be classified as careless or dangerous driving and result in penalties if carried out unsafely. Drivers should only pass on the left when it is clearly allowed and safe to do so.
