We have seen many articles, some from law firms stating ‘Filtering is legal’ these articles have caused much celebration amongst bikers but how many of those articles have gone on to define the legal definition of filtering?

Rule 88 Highway Code; when filtering in slow-moving traffic, take care and keep your speed low.

This rule doesn’t really help us define filtering because the measure of ‘slow’. ‘low speed’ and ‘care’ is subjective and we may all have different interpretations of their meaning.

Civil law,

Should your filtering result in a claim either by you or against you it can be influenced by previous judgements this is called case law however by looking through the cases linked below you will see each case is taken on it’s own merits.

Note; links take you to an external website, I am not responsible for the content of that website nor am I in any way promoting the website or the services they provide.

Harding-V-Hinchcliffe-1964 Clarke-V-Windchurch-1969 Worsford-V-Howie-1980 Fagan-V-Jeffers-2005

Davis-V-Scrogin-2006 Woodham-V-Turner-2012

In summary if it goes wrong whilst filtering don’t expect the law to automatically back you up or that you will be deemed to be in the right just because someone said ‘Filtering is Legal’ what we need to do is to care for ourselves and do our best to prevent it from going wrong.

Getting it right.

Filtering is risky because drivers are not expecting us to be passing them, they won’t expect it because it doesn’t occur on a regular basis it isn’t normal their focus is more likely to be on the queue ahead or maybe a gap in the next lane or even a turning or entrance so we need to be prepared to have not been seen, stress can also be heightened both for the driver who’s journey may have been delayed and by the rider who may feel threatened or at risk due to the limited space to manoeuvre.

Keep your cool

Getting angry may seem like a just response to an offending driver but with your judgement temporarily clouded by ‘red mist’ you are likely to make a mistake or poor judgement call resulting in a crash of your own making, don’t force your way through flashing headlights revving engines or using your horn this is unlikely to make drivers help other riders in the future.

Risk vs Gain

Before starting to filter ask yourself what you will gain and will that gain outweigh the risk, e.g. Passing a few cars waiting at a junction, passing a queue and then you turn onto a different road or into a petrol station, starting to filter when traffic is about to move off once you have started filtering be prepared to give it up and join the traffic flow.

In this clip the lanes narrow as they change from two to three lanes and drivers start to change lanes it’s time to stop filtering and join the traffic flow.

Exit strategy

Before starting to filter are you certain you can get through, have you got somewhere to go a gap to move into, don’t get stuck beside a large vehicle especially where lanes narrow or a bend such as on the approach to a roundabout.

In this clip the bus is making the gap narrow although I could have squeezed through but by being patient and waiting for the silver car to pass the bus the gap opens up and I can pass with ease.


There isn’t a number to give you as it will depend on the conditions so consider these points; the faster the traffic is moving the quicker they can change lanes or turn, the faster we are moving the longer it will take us to stop it also becomes harder to make sudden manoeuvres we also need to consider pedestrians as they will not be expecting to come across a moving vehicle in stationary traffic. Speed differential, the difference between you and the vehicles you are passing needs to be managed carefully and kept low.

Gaps-V-Pinch points

A pinch point where a pair of cars are side by side may seem like a risky gap to go through but in reality, providing the gap is wide enough for you to pass through it is safer than passing a car with an empty lane next to it as it increases the likelihood of the driver changing lanes.

In this clip passing between the brown car and van is relatively low risk as neither of them are looking to change lane the greater risk comes from the silver car in lane one, it’s close to the centre line and there is a gap for it to move into in lane two. Again with patience I make sure I know what the driver is going to do before committing to pass.

U & Right turners

Just as when there is an empty lane on dual carriageway an empty lane on a single carriageway is an invitation for a driver to make a U-turn or right turn especially in long queues this is where an appropriate speed can allow you to stop and avoid these drivers even if they do check their mirror before manoeuvring their focus will be on looking for a gap in the traffic coming the other way. A Right turn manoeuvre is the most common manoeuvre by drivers who are involved in collisions with motorcycles.

Blind Spots

Ok we all know all vehicles have blind spots, actually it’s a large area either side of the vehicle not a spot and to pass other vehicles we have no choice but to pass through that blind area, if you are passing moving vehicles avoid lingering in the area not visible in their mirrors.

The diagram gives us an idea of those blind areas this varies between vehicle type and size, the short clip shows how I have positioned myself to ‘be seen’ by both drivers, how do I know this because I can see them in their mirrors.


Some Rules to consider

Pedestrian Crossings Rule 191 You MUST NOT overtake (this includes filtering) the moving vehicle nearest the crossing or the vehicle nearest the crossing which has stopped to give way to pedestrians.

Double white lines where the line nearest you is solid Rule 129. This means you MUST NOT cross or straddle it unless it is safe and you need to enter adjoining premises or a side road. You may cross the line if necessary, provided the road is clear, to pass a stationary vehicle, or overtake a pedal cycle, horse or road maintenance vehicle, if they are travelling at 10 mph (16 km/h) or less.

Areas of white diagonal stripes Rule 130 or chevrons painted on the road. These are to separate traffic lanes or to protect traffic turning right.

  • If the area is bordered by a broken white line, you should not enter the area unless it is necessary and you can see that it is safe to do so.
  • If the area is marked with chevrons and bordered by solid white lines you MUST NOT enter it except in an emergency.

Advanced stop lines Rule 178. Some signal-controlled junctions have advanced stop lines to allow cycles to be positioned ahead of other traffic. Motorists, including motorcyclists, MUST stop at the first white line reached if the lights are amber or red and should avoid blocking the way or encroaching on the marked area at other times

Hatched areas might seem like a useful lane to filter in but they can be littered with tyre puncturing debris.

Hatched area