Overtaking - lifesavers and following distances

One of my least favourite expressions is "if I didn't overtake, I might as well be driving a car", as if a motorcycle is an automatic licence to overtake.

Personally, I believe that there's nothing more dangerous that we do on a bike than overtaking. Overtaking is inherently high risk. However good you are, you can only make it safer, you can't make overtaking safe.

Think about it for a moment - not only is it just about the only accident that you'll accelerating into, but you're relying on other drivers to behave in a predictable manner. It's often when the driver you're passing does something you haven't expected that it goes wrong, and then you're carrying one heck of a lot of speed.

So I tend to think that everything we do that decreases risk when overtaking is a good idea. And one of those good ideas is knowing what's behind you, which is probably the area that most riders forget to check! "After all", they reason - "if you are overtaking you're going faster so the hazard must be in front of you, no?"

Well, actually, no! If you're thinking about an overtake, so will someone else be. The most obvious candidate is another bike but there are plenty of cars out there these days with stunning acceleration - ask Jeremy Clarkson!

So recently on Visordown the discussion raged again - lifesaver or no lifesaver before pulling out to pass another vehicle?

The crux of the argument is whether you can believe in what is sometimes called 'mirror history'. The idea is that if you check your mirrors often enough, you will have seen something catching you and should know if there is anything in your blindspot.

I'm afraid I don't really go with that - there are too many things that can go wrong, and so I'm a believer in checking the blind spot as a fail-safe. However much you look in your mirror it can only tell you what's behind you, not what's alongside you.

The problem is that as the road gets busier, the chances of you correctly filling in the information starts to go down dramatically. As one contributor put it:

"I find there are some situations where I think a shoulder check is essential and some where they aren't needed. It all depends on the complexity of predicting the future. If you have gathered a stable but dynamic, developing 'picture' of the space around you from the information gathered in the period before the manouevre - other traffic, behaviour, speeds - and can confidently predict that nothing will adversely affect the manoeuvre... then you make the move without a shoulder check. If the situation is one of high complexity then you make the check."

That's about the way I'd see it - but given the human propensity for making mistakes, I'd have to be very, VERY certain there was nothing around me NOT to do one.

Look at it this way. You wouldn't rely on three or four glimpes through a tall hedge to decide that is was safe to drive straight out of a minor road across a main road, would you? You'd look properly before committing yourself. Mirror checks can only give you the rearward equivalent of these glimpses. But only a shoulder check can show you what is actually IN the blind spot.

There are two problems, if you discount the obvious one of failing to look often enough. Working out speed and distance - and then deciding when that vehicle will arrive along side you. to do this

You'll need to look into the blind spot to see the bike or car that comes up so quickly that you don't spot it between regular checks. Do some sums. At 60mph you're travelling around 27 metres per second. Say you check your mirrors every 5 seconds (and that's pretty enthusiastic mirror checking, too) - in that distance you've travelled around 130m.

Now, what if there is a bike (or possibly even a police car) doing 120mph coming up behind you? If you check your mirrors four times at 5 second intervals, with the final check when it's along side you, the first time you check it'll be over 500m back - more than a quarter of a mile. There's not that much chance you'll spot it - think about how mirrors make things look further away!

Second check and it's now 270m back - that's still more than the length of two football pitches - there's a pretty good chance you still won't see it if there is a lot of other traffic in the lane.

Next check will be when it's 135m behind you. Sounds easy enough to spot, but if it's in the same lane, and there is another vehicle close behind you, will you see it? And even if you do, if you didn't see it in either of the two earlier checks then what you don't know is how fast it's going.

On your fourth check, the car/bike is alongside you. Scary.

Another problem with mirror history that you may find on a multilane road if you are in the middle lane is that a vehicle will come up fast on your left then do a sudden swoop from left to right to switch sides to the outside lane of three - so that your checks in your right mirror won't have shown it, and even mirror checks to the left won't have warned of the driver or rider's intention. This can also happen as you pass the "on ramp" on a motorway or dual carriageway.

It's also saved me several times on motorways when a driver has moved up from behind and then sat just alongside in my blind spot so he's not visible in the mirror - the only way you'll spot that is a blind spot check. In fact, updating this article today, it happened on the motorway just yesterday morning - I'd watched a car come up in the outside lane and move just ahead of me, then slow down slightly and sit there, boxing me in. Whilst I was concentrating on working out where I could safely move out to avoid the slower vehicle ahead that I was catching, what I hadn't noticed was that the car that had been following me in the same lane a moment earlier, had now moved to the outside lane as well - right into my blindspot. So when the first car finally put his foot down a bit and I thought I had a chance to move out, a quick glance into the blind spot before I committed myself showed me that the gap was already occupied by a car.

So, things can change very fast indeed on motorways. Even if you think you know what's there and it's going to stay there, you might be wrong. Read this:

"The dangers of the assumption above were brought home to me when I was being observed a few years ago. We were on our way back and it was getting dark; my observer was riding a Pan and another Pan had caught up with us which I hadn't seen; this second Pan had gone past the observer who had moved over accordingly, so the lights I saw in my mirror weren't his at all; thus there was very nearly a meeting of fairings when I pulled out to overtake, thinking that my observer had anticipated the overtake and was ready to follow me through, when, in fact, it was the "foreign" Pan overtaking me."

So, given the safety benefits, why are some riders and instructors so dead-set against them?

One of the main objections levelled against the blindspot check before committing to an overtake is that it's potentially dangerous if the car suddenly slows down.

My take on this is that if the car slowing puts you instantly at risk, you're too close. Full stop. No argument. No "if's", "but's" or "maybe's". If the car slows and you are inconvenienced by that, whether you are looking over your shoulder or not, you should have been further back.

Quite apart from the blindingly obvious point that if you can see something that might force the car to slow, you shouldn't be there, if you are the least bit worried about running into the back of the car when planning an overtake, you won't be thinking about the other problems the overtake is setting you - it's a form of target fixation. Given the ever-more crowded state of the roads, the chances of an overtake being completely free of oncoming traffic is going down every day - you need more attention AHEAD of the vehicle you're planning to pass and behind you too, not less by worrying about running into it.

It's been claimed that looking behind takes too long. Some quoted two seconds as the time it takes to look over your shoulder. I wouldn't be spending two seconds looking behind me either, even at a safe following distance. If it takes you that long to do a shoulder check, you're being too precise about it AND looking too far behind.

Half the reason for this argument on the issue is that many riders still think that a lifesaver is a long look behind. That was what riders were supposed to do until fairly recently, thanks to the DSA's reluctance to acknowledge bikes had mirrors till the late 90s, but it's really not necessary. A lifesaver is simply a chin-to-shoulder blind spot check timed before an important change of position, into a potentially dangerous position. In other words, it's the timing rather than the action.

It's simple enough to combine a mirror check and follow through straight into a blind spot glance. Your head check has now filled in the entire picture alongside and behind. I really cannot see why people are so against the idea of doing them. If it's timed correctly it's no more dangerous than looking in the mirror.

Whilst I'm on overtakes, I'll comment on the habit of moving up to a very close "overtaking" position behind the vehicle ahead when looking for an overtake. It's recommended by police instructors and can be seen demonstrated on the Bikesafe 2000 video. For my liking, that position is far too close - at one point on that otherwise excellent video, there is barely a single hazard line between the bike and the car ahead. Even their safer "following" position is about half the distance I'd like to keep between me and another vehicle.

So, I'd double the distances shown in that video - my following position would be around the 2 second minimum safe distance, and my closer up overtaking position around 1 second back.

Whilst it's true that the holding a more distant 1 second "overtaking" position means you are accelerating from a greater distance, with good timing you don't need to twist the throttle so hard because you can get something of a "run" at the overtake. Hanging back further allows you to catch up in the final part of the corner, and often makes it easier to pass without excessive speed or any wasted time. If you are too close, it's hard to accelerate before you are wide and clear, which tends to lead to big throttle openings.

In reality, if you overtake from further back, what you have to avoid is carrying too much speed into the overtake. If a situation starts to develop that looks awkward, you may have to pull back in. If you can't pull back in, you are passing with too much speed. You should pass slowly enough that you can bail out if you need to. I can't begin to say how many times I've been in the middle of a pass and something goes wrong that I've had to brake to avoid, and I don't just mean misjudgements on my part - but brain out manoeuvres by the other driver.

If you yo-yo between the close "overtaking" position and the more laid back "following" position, you need to think how incredibly distracting that can be to the driver you are trying to pass, particularly if you have lights on. And something else that's rarely mentioned is that as soon as you move up, the car behind YOU maintains their own "is that a fly on that bike's numberplate?" following position, so dropping back becomes problematic, if not potentially dangerous - another reason for not getting too close in the "overtaking position" and finding yourself the meat in a sandwich.

Following too close through a bend is a mistake too, as most drivers decelerate until they can see their way out of a corner - if you're too close, that means you decelerate too and end up at lower revs than you meant to.

Slow + high gear = longer time to make the pass when you finally go.

Another factor which is frequently ignored is that cars are massively more powerful than they were even 10 years ago. Even something that looks like it ought to trundle out of a corner like a massive 4x4 can often accelerate pretty quickly. Yes bikes are faster too, so we end up using ever higher speeds to make up the pass.

Even a good overtake is potentially dangerous - so it makes sense to make them as safe as we can, not to risk all on a hurried and botched pass.