How to filter on a motorbike: Expert advice to help you make proper progress in traffic

It’s a question we get asked a lot: how do you filter safely and legally on a motorbike? As cars and 4x4s get ever fatter, the lanes we use for filtering (otherwise known as ‘lane-splitting’) are becoming narrower, the margins for error tighter. So more than ever the slickest and safest way to slip through traffic is to slow everything down.

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On dual carriageways and motorways aim to travel at no more than 20mph faster than the traffic you are passing. That means your max speed will be 20mph if the traffic is stationary; 30mph if it’s moving at 10mph. This speed differential, the relationship between your speed and that of the other traffic, is the ticket to a serene and effortless passage.  

Yes, the key is not to rush but to give yourself the space and time to question and ask ‘what if?’. What if a car in the right-hand lane suddenly fills the gap that’s appearing in the middle lane? What if an angry driver ahead, perhaps one who resents filtering motorcycles, decides to squeeze the gap you are aiming for?  

If you question rather than assume, your speed will naturally fall within the 20mph differential. 

Traffic hates a vacuum anywhere but in town especially any gap is likely to be quickly filled by frustrated drivers eager to grab any opportunity to progress. When you filter past junctions expect cars to be emerging or forcefully turning across your path, quite likely both.

Pedestrians, too, live on another planet to motorcyclists and can be wildly unpredictable, with any gap in the traffic becoming an impromptu crossing for runners, school kids and shoppers. If one emerges more may follow – all erroneously believing in safety in numbers.

Create a presence: be ready to use your horn to wake up a dozy driver, who these days is more cocooned than ever from the world outside his car. Take any perceived aggression out of the situation by a wave of acknowledgement afterwards.  

Above all, slow it down, give yourself time to assess and be smooth. Riders who don’t think are normally the fastest filterers. For a while.   

Are you allowed to filter through traffic on a motorbike?

Absolutely. The Highway Code says “You should be aware of what is behind and to the sides before manoeuvring. Look behind you; use mirrors if they are fitted. When in traffic queues look out for pedestrians crossing between vehicles and vehicles emerging from junctions or changing lanes. Position yourself so that drivers in front can see you in their mirrors. Additionally, when filtering in slow-moving traffic, take care and keep your speed low.”

Top tips for filtering on a motorcycle

• Check your speed when filtering; are you within the maximum 20mph differential?
• Question, scan and try to identify gaps in the traffic where traffic may cross your path
• Watch out for any potential surface changes such as painted white lines, and think about how they could affect you
• Practise using the horn: when you need it, you need to know where the button is first time

Filtering FAQs

Is filtering on a motorbike legal in the UK?

Yes. You do need to ensure you’re doing it safely, though.

Is filtering the same as overtaking?

In its most simple terms, yes, filtering is simply overtaking. With that in mind, be very careful not to cross solid white lines.

Are motorbikes allowed to undertake?

Passing a vehicle on the left (which could also be called undertaking) is only allowed either when the vehicle ahead of indicating right, or when traffic in the right-hand lane is moving slower than your lane. Source: White Dalton solicitors

Additional reporting by Tim Thompson