Motorcycle Filtering Tips on Motorway or Dual Carriageway

On my daily commute into London by motorcycle, I invariably find myself having to filter a lot. Some of this is around suburban roads, some on two or three-lane A roads, and some in the tightly congested centre of the capital. Today, I’m going to specifically discuss filtering tips (lane-splitting tips for US readers) for riding on dual carriageways and motorways.

Filtering Law – What is legal?

In the UK, it is perfectly legal to filter through slow-moving traffic to make progress. In fact, it is positively encouraged when learning to ride and many a rider will fail their test through ‘failure to make progress’. There are however a few instances where motorcycle filtering is illegal:

1. You must not cross an unbroken white line. More specifically, no part of you bike or body should cross or overhang an unbroken white line, except when negating a hazard (stationary vehicle or cyclist, horse, road maintenance vehicle travelling less than 10mph) and it is safe to do so. Slow-moving traffic is not a ‘hazard’, I’m afraid.
2. You must not overtake where there is a no-overtaking sign. Obvious really.
3. You must not overtake the lead vehicle at a pedestrian crossing or within zig-zags. Less well known, but not applicable to motorways.
4. You must not endanger or cause of other vehicles to change course or speed.

Undertaking vehicles on the near side is not illegal, it is just not recommended, so care must be taken. If you ride like an idiot weaving in and out of lanes, you could be booked for careless driving or possible dangerous driving. It is also perfectly legal to ride on cross-hatched areas and central reservation if they are surrounded by a broken white line. However, the Highway Code says you ‘should not’ unless it is necessary and safe, so this action may be held against you in any insurance claim following an incident. These areas also build up with debris and loose stones, so be careful.

Check out my video on the legalities of motorcycle filtering:

Speed

When filtering, appropriate speed is crucial. Obviously, you should never exceed speed limits, it is recommended to keep your speed to within 10-15mph of the traffic you are in. So as traffic slows, reduce your speed, as traffic speeds up, raise your speed in line. However, you should not filter through traffic travelling faster than 40mph. Above this speed you will not be able to react fast enough should vehicles suddenly change lane. It is also wise to tailor your speed to the gap you’re filtering through, slow down for tighter gaps.

Traffic jams are full of frustrated drivers who are prone to doing irrational and stupid manoeuvres. Care must be taken and you must be prepared to stop at a seconds notice, which simply isn’t possible at high speed.

Motorcycle Filtering / Lane Splitting Tips

Let’s run through some general tips for filtering on the motorway, that I’ve picked up on my daily commute:

1. If you approach some traffic bunching up ahead, don’t filter immediately. Invariable some drivers will spontaneously change lanes to try and keep moving. Hold back, then filter between the two lanes once they are both travelling at similar speeds.
2. Aim to filter between the two outermost (fast) lanes. Nearside lanes tend to be hogged by wider trucks and you can get caught up with those joining or leaving the motorway at junctions.
3. Anticipate braking at all times, but be wary of covering the brakes lest you reactively grab a fist full in a panic. Keep in a low-ish gear, to make use of engine braking and give you acceleration should you need to zoom out of a closing gap.
4. Never enter a closing gap, back off and wait. The road may just be narrowing, or there may be an unseen hazard ahead cars are circumventing, or they may be planning a lane change.
5. Scan the road ahead, try to spot those about to lane change; look for indicators, front wheels angled, cars positioned far over to one side of the lane, or one lane moving faster than another. If you do spot someone about to pull across you, slow down, honk your horn, make your presence known.
6. Take heed of gaps in the traffic. If a gap reveals itself, expect a car to fill it, possibly cutting across you into it or joining from the nearside.
7. Be mindful of the road surface between lanes. It’s often uneven from joins in the tarmac, will have painted white lines that are slippery in the wet and bumpy cats eye’s. In the winter, it will be less trodden, so may have ice, snow or slush, in which case avoid filtering and just stick to clear tyre tracks.
8. When following other bikers filtering, try to look beyond them and gauge every gap for yourself. Don’t tail them blindly staring at their back wheel. Gaps change, new hazards can reveal themselves and there’s no guarantee they’re a sensible rider…

I hope some of the above filtering tips are useful to you. In future posts, I’ll cover filtering in the city and suburban roads off the motorway. If you have additional advice and tips, please leave a comment, I’d love to hear from you.

Read the next instalment: Motorcycle Filtering Tips in the City.

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