Overtaking

[Dilbert]

Can't see the point in pulling out and then nailing it, you would lose traction just as you cross the (broken obviously) white lines i.e. just at the point you need the most traction.

All the bike cops I've seen look for a space then accelerate smoothly out past the car and then back in, jerkin it about ain't no good for no-one

[matthelliwell]

Can't see the point in pulling out and then nailing it, you would lose traction just as you cross the (broken obviously) white lines i.e. just at the point you need the most traction.

All the bike cops I've seen look for a space then accelerate smoothly out past the car and then back in, jerkin it about ain't no good for no-one

Well then you'd accelerate after you've crossed the white line? The idea is, I think, to avoid accelerating rapidly towards the car you want to overtake and then not being able to abort the manouver if it goes wrong.

[Cie]

Well then you'd accelerate after you've crossed the white line?

...and why would you ride over the white line? They're slippy and the change in surface (and it's raised nature) will make the bike unstable.

[matthelliwell]

...and why would you ride over the white line? They're slippy and the change in surface (and it's raised nature) will make the bike unstable.

Well that depends on how wide the road is. There aren't many roads I can think of where I'd be happy to pass between the car and the white line unless I was filtering. I prefer to give the car a bit of a wider berth.

So what do other people do?

[Cie]

Oh sorry, poor explanation, ride between the gaps in the white lines.

[icenian]

Oh sorry, poor explanation, ride between the gaps in the white lines.

Maybe he rides a Varadaro, and it won't fit through the gaps?

[matthelliwell]

Oh sorry, poor explanation, ride between the gaps in the white lines.

Ah yes, that makes much more sense.

[Dilbert]

I always prefer to be on the other side of the white line, you never know when you're going to meet some lunatic coming the other way on the wrong side of the road, much safer that way

Sorry, but this whole move out, then accelerate sounds too much like bad planning, the only time I would do this is when overtaking a large truck in the car when I can't see over or round it, surely the safest option is to plan your attack before you approach the car you're going to overtake, rather than wait until you're right on it's tail

Maybe this approach was developed for sportsbike riders who have their head tucked down between their knees and can't see past the front of their fairing

[icenian]

OK, I'll play devil's advocate

Let's assume that when you are to the left of the white line, you are directly behind the vehicle you wish to overtake. Let's also assume the "2 second rule" (stay at least 2 seconds away from the rear of the vehicle in front to avoid becoming street pizza if they brake suddenly).

Now, if you start off 2 seconds from their rear bumper, how can you accelerate before pulling out? Doing so will take you within the 2 second gap, which is dangerous.

So, you need to start off with a larger gap, so that even after you accelerate you remain more than 2 seconds away from the rear of the vehicle. Note you'll actually have to maintain much more than a 2 second minimum gap, as if you are doing (say) 50mph and they're doing 30mph, if it goes pear shaped and you can't get past, then you need to be able to brake back down to 30mph and still be at least 2 seconds away from them when you have finished braking.

To clarify that last point with an example. Car in front doing 30mph. You doing 50mph and just about to pull out to pass car. Tractor and trailer then pull out blocking the road, so you can't overtake, and the car also has to brake hard. You are going faster and require 175ft (53m) to stop versus their 75ft (23m); that extra 100ft (30m) will be covered as you decelerate from 50 to 30mph, and the average speed during that time should be about 40mph (59ft (18m) per second), so you require an extra 1.7 seconds. So, if you were within 3.7 second of the rear of the car, you are now in the sh*t.

So, if you want to accelerate significantly prior to pulling out, you need to be a long way back behind the car you want to pass. In that example you want to be nearly 4 seconds back from the car at the point you pull out, so you would probably have been an absolute minimum of 6 seconds behind when you started to accelerate. That's a minimum 4 seconds, which is over 175 feet (53m), further back from the car than you could have been, if you had been following at a safe 2 seconds with the aim of pulling out prior to accelerating.

To make up for this, not only does your extra speed (a paltry 20mph in this example) have to compensate for the extra 175 feet (53m) you need to cover, but also is has to make up for the fact that you'll start your manouver 4 seconds later that you could have done -- because you're so far back down the road you have to wait longer so see if it's clear.

[N.B. I used Highway Code stopping distances and simplified assumptions about deceleration rates during braking, and doubtless other dodgy fizzicks (which my spelling checker wants to change to doggy pizzicato ). These figures and assumptions can be refuted pretty easily. Question is, can they be refuted in such a way as actually makes a significant difference to the argument above? Especially when its cold and greasy and the car drive in front just stomps the brake pedal as they've got 4 wheels and ABS...]

[Steve C]

I've been watching myself since reading Dave's post a week or so ago and you're all right.

There are times when pulling out and then accelerating is the right move and there are times when I might pick up a bit of momentum before moving out if I can see enough over the vehicle and there are times when I pull out to see - say further around a bend - and then make my decision, so I'm not accelerating at all. Each time is different, isn't it?
The white lines can create a bit of instability but only a tiny amount even if I'm on a bend and slip right off them. I would rarely have my attention on the spacing when overtaking at 50+ and if the surface/conditions were such that I needed to be knowingly aware of them, I doubt very much that I'd be overtaking.

I would though, always be constantly monitoring and checking from pull out to pull in and would only be out there if there was a way back within visible safe distance.


And it's my guess that we all do something like that?