Rapid Technical Series information sheet


There are risks to filtering, but once you know what they are you’re well on the way to staying safe. Rapid Training’s boss Gary Baldwin explains the principles to John Westlake.


John Westlake

John Westlake is one of the UK’s most experienced motorcycle journalists. The former editor of Bike and Ride has road tested almost every bike made since 1991 and is a contributing editor for Bike and Classic Bike.

Gary Baldwin_Rapid founder.jpg

Gary Baldwin

Gary Baldwin is a crash investigator, ex-motorcycle cop, former racer and director of Rapid Training. He’s a blisteringly fast road rider and the man behind Rapid’s no-nonsense approach to fast, safe road riding.

JW: Basic question first: should I filter?

GB. Yes. Getting through traffic quickly is part of what a bike is for and I believe we should do it. It’s legal and there’s no reason why it should be dangerous provided you’re aware that other people might not be expecting you to be where you are.

Is it really legal? A lot of riders seem to think it isn’t...

It is legal in the UK, but it’s a grey area. The Highway Code says “when filtering in slow-moving traffic, take care and keep your speed low” so it all depends on the definition of slow-moving and what speed is low. So, technically, you can’t say that filtering at 70mph is careless driving, but it’s important to consider if you’re being reasonable – if you’re hit when filtering, that’s what you’ll have to prove. If you’ve just overtaken a car going 10mph faster than them, they won’t bat an eyelid because it appeared reasonable to them. But if you went by 40mph faster, that’s when you might lose that reasonableness. And when you’re on your back staring at the sky, those people will be only happy to tell the coppers what they thought of your filtering.

So if I keep it to 10mph above the traffic I should be ok?

Probably, but not necessarily. The biggest error people make is going too fast at the wrong time. Filtering isn’t done at one speed - you should be altering it constantly depending on what the situation is. So when you’re coming up to junctions, entrances, exits and so on, you need to back off and wait and see – then 10mph could be much too fast. If there’s a gap you can’t see into, the car about to stick his bonnet out can’t see you. Beware.

Where is filtering most likely to end in tears? 

Most filtering accidents happen in towns (as opposed to multi-lane roads). Here it’s  predominantly the case of a car pulling out of a junction on your left that you haven’t noticed, or the car turning right across your path. It’s at that point that our choice of speed makes a big difference because it determines if we can deal with the situation without ending up on the bonnet.

So motorways are safe filtering zones then?

No. On multi-lane roads, the common scenario is car drivers hanging out in lane three until the last possible minute and then deciding that they want to come off at this exit. They take a cursory glance in the mirrors, see a gap and dive across. Fundamentally, space is dangerous when you’re filtering because some toe-rag is inevitably going to try and make use of it. If the traffic has stopped and the spaces between cars have disappeared you still can’t relax because there’s a risk that someone will open a door into your path.

What speed can I carry on filtering up to on motorways?

Everyone tends to have a speed at which they’re comfortable filtering at on multi-lane roads. There’s not a set number beyond which it’s dangerous - it’s down to personal judgement. Personally, once speeds get up to about 40 to 50mph I start to become slightly uncomfortable. If traffic is moving heavily in queues at 70mph and you want to dive down the middle, good luck. I’m not that brave any more.

Should I cover the front brake?

Personally, I don’t cover the front brake while filtering unless the situation is tetchy. Instead, I just use a responsive gear so there’s plenty of engine braking if necessary. But it’s down to personal feel.

What’s the etiquette if another bike catches me up while filtering?

Let him pass as soon as you can. The fewer bikes there are around, the more risky filtering becomes because drivers won’t expect you. If there’s a good through-put of bikes, people tend to become bike aware. That’s why if a bike comes up behind me I’m only too happy to let them pass. He can wake all the car drivers up and I’ll follow when they’re more aware - a bit selfish I know, but you make your own luck.

Where do I filter on motorways? Between lane 2 and 3?

I think that between lanes two and three is the best place because my experience is there are fewer lane changes, though I’ve got no formal evidence of that. Also there’s usually more space because there are fewer lorries. I don’t like going between the off-side and the barrier because there’s a vibroline there that I don’t want to ride over and because of all the dead badgers, wing mirrors etc. Unless it’s absolutely stationary and you’re doing 10mph, that’s a no-no.

Anything else to bear in mind?

At night it’s worse because as a driver when you look in your mirror, what do you see? A load of lights. You just put your indicator on, you know there’s a gap and over you go. Or you don’t indicate – lots of drivers don’t. Another thing to consider is that at higher speeds, the cars can change lane faster.

Graham Sass