Is it illegal to filter on a motorcycle?

Traffic on motorway

There is a common misperception amongst motorists that it is illegal for motorcyclists to filter between lanes of queuing or slow-moving traffic. 

This is not the case. 

Rule 88 of the Highway Code confirms a motorcyclist is entitled to filter “in slow-moving traffic” so long as it is performed safely and the rider takes care and keeps their speed low.

Safety tips for motorcyclist filtering through traffic

Safe filtering really requires you to carefully balance risk against progress. Accidents often occur where other motorists are not aware of your approach. You need to make sure you are visible, and that you afford other motorists a chance to see you.

1. Speed – and perception - when filtering through traffic

A good starting point is speed. You must be aware of your actual speed and the perception of your speed to other motorists.

Your speed will depend upon various factors including:

  • road conditions
  • weather conditions
  • experience

However, as your speed increases, braking distance increases and the prospects or time for you to be seen by other motorists in their mirror decreases.

If a car is stationary or crawling at less than 5mph, a bike passing at 20mph will appear to be travelling fast.

This perception could be crucial where an accident takes place and you require to rely on supportive witness evidence.  As a result, it is important to be aware of the impact the perception of your speed may also have.

Accordingly, it may be advisable to filter through slow-moving traffic at a speed of no more than 5 – 10 mph more than the traffic. This is only a rough rule of thumb, but may help to limit the prospects of wrongdoing being attributed to you or your actions in the event of a collision.

2. Road layout and risks of filtering

The layout of the road is also essential when considering the risks of filtering. Filtering should not be attempted when there are:

  • Solid white lines on road
  • No overtaking signs
  • Approaching a pedestrians crossing

Failure to comply with the road markings and signage could see your manoeuvre deemed to be a dangerous overtake, rather than filtering, which could result in criminal charges being brought against you.

It is also important to bear in mind the space around you when you are filtering. 

3. Dangers of other motorists changing lanes

Frustration caused by slow-moving or queuing traffic applies equally across all categories of motorists.  As a result, it is common that other motorists will also change lanes to try and further their own progress.

Although their motivations are aligned with those of a filtering biker, the frustration caused by the lack of their (the other motorists’) progress can result in an increased risk of erratic manoeuvres (lane hopping).

Motorcyclists must always be aware of the dangers posed to them by other motorists changing lanes and crossing their direction of travel. 

You must be alert when filtering and ensure you are travelling at a safe speed. What is ‘safe’ depends entirely on the conditions and requires you to make a careful decision as to whether to stop and wait, walk the bike through, or to continue at a slow speed.  

Conclusion: filtering is a judgement call for motorcyclists

It goes without saying that safety on a motorcycle is paramount. However, the assessment of what is or is not, safe is a subjective question that really depends on the individual rider’s views, experience and attitude.

It may be easier for a rider to view this question of safety on the basis of balancing the risk of filtering against the potential progress that is likely to be gained.

Remember: filtering poses an inherent risk of accident.

When filtering through traffic, there is an inherent risk that an accident could happen. To minimise that risk you should ensure:

  • Road layout allows for filtering,
  • There is sufficient space to complete the manoeuvre (including knowing where you can re-join the traffic)
  • And arguably the most important consideration: you and the slow-moving traffic should both be travelling at speeds that are safe for filtering.

If an accident occurs involving a motorcyclist whilst they are filtering, it is much more likely that the motorcyclist will be injured than any other party. 

Please ensure you consider our advice next time you are thinking about filtering and properly balance the risk you may expose yourself to against that time you might save.

Your wellbeing and livelihood is more precious than any time you might save!