Safe following distance?

[James Deuce]

I think it's because when an object is just coming towards you in a straight line, the only indication it is moving (and hence attention-grabbing) is the fact that it is growing in size. Because motorcycles are narrow, this effect is pretty negligible compared to a wide car. When you swerve like that, you're moving across the field of view, so it's a big, obvious movement that they can see very well.

It's called motion camouflage and it's how dragonflies hunt. There's a lot of literature about motion camouflage in relation to motorcycles. The same effect causes people to try and cross level crossings in front of thousands of tonnes of freight train. Trains stay relatively static in size compared to the scenery as they approach, just like bikes.

[swbarnett]

I think it's because when an object is just coming towards you in a straight line, the only indication it is moving (and hence attention-grabbing) is the fact that it is growing in size. Because motorcycles are narrow, this effect is pretty negligible compared to a wide car. When you swerve like that, you're moving across the field of view, so it's a big, obvious movement that they can see very well.

Exactly. We are all predators genetically, our brains are queued to detect lateral movement. Anything coming towards us slow enough relative to it's size is effectively not moving.

[sinned]

But, there are a couple of instances where following closely makes sense.

In a target / risk rich environment, for example, heavy traffic in the morning - where the sun is behind you - think of this from the point of view of someone pulling across your lane to execute a right turn who will not see you with the sun in their eyes, then riding in a car's "shadow" can make sense.

The logic is that the car turning may not see you at all, but they are more likely to see a car - so, assuming you can see over the car, you can close the gap.

Okay, so point is, you sit in the car's "shadow" - since you cannot safely project your presence, you let the car do it for you.

This makes sense to me and I often close the gap at an intersection to get protection from the car in front if the car on either side of the intersection hasn't seen me. It is risk management; I am increasing the risk of not being able to stop and minimizing the risk of getting wiped out.

Really?
I always cover the front brake. My forefingers are always resting on the clutch and brake levers. It's just where they go when I hop on a bike.

I find it too difficult to hold the bars and a steady throttle with one or two fingers resting on the levers. It sounds like a good practice but doesn't work for me.

It's called motion camouflage and it's how dragonflies hunt. There's a lot of literature about motion camouflage in relation to motorcycles. The same effect causes people to try and cross level crossings in front of thousands of tonnes of freight train. Trains stay relatively static in size compared to the scenery as they approach, just like bikes.

I am right into weaving and do it at most intersections where traffic is waiting. Sometimes wonder what people watching think I am doing.

[Clubbie]

Really interesting thread so far! I have a question about the weaving technique, would you do it on the open road approaching a side road?
If so tell me about how far out you'd do it from, how much you'd weave etc.
I ride like a nanna so assume my speed is 95-100Km/h

[newbould]

I have noteced a few times commuting that I am commanding more respect than usual coming up to junctions - then realised that I am being tailed by a 4wd - so i am in its "shadow" in front of it. So maybe slowing back from the vehocle in front could also increase your visibility. Also worth noting that if you are being blinded by a low sun then you are very visible to drivers looking at you with the sun behond them - it is when the sun is behind you that you become invisible - like wwII fighter pilots attacking from way high up with the sun behind them - not that I've ever been there! I also extend following distance when I am being tailgated so I hope I can slow more gradually if needed. I do like the idea of stopping alongside the vehiocle in front rather than being meat in the sandwich - thanks for that tip.

[LBD]

Following distance, clear visibility/stopping distance are both different.

The 2 second dry, 4 second wet following distance guide lines have kept me safe many years riding.

Following distance is not related to visible distance, if you can see the road infront of you, even if part of that road is occupied by the car or cars in front of you. I always watch both the car(s) in front and the road ahead of them.

Covering the brake? Not always when riding but always following or on twisties or blind corners or unfenced road or where there is good chances of other surprises

[James Deuce]

Also worth noting that if you are being blinded by a low sun then you are very visible to drivers looking at you with the sun behond them - it is when the sun is behind you that you become invisible - like wwII fighter pilots attacking from way high up with the sun behind them -

In addition to that point, if you have your headlight on in that situation you are indeed completely invisible as the headlight prevents you from being seen in silhouette.

[caseye]

Wow,some damn fine ideas out there, the consensus is that the simple 2 sec rule is not actuially enough to make sure you can stop in time.
So 12 senonds seems more adaquete, but may still not be enough time.
These days, I leave a big gap, 1-200m's in front of me( on motorways) a bit less in town and to hell with the que jumpers and the tailgaters who come roaring up behind me in their tin cans.
I even go so far as to hit the brakes hard if i can't see their number plates in my rear views.though this is not advisable practice when being tailgated by a car full of mob members.
I have found that over the days, weeks, months since I've started taking my current route to work that many people have left the gap and adopted that gap for themsleves behind me.And this in Dorkland!
Road conditions, traffic flow and driver attitude all have to be considered, if you don't allow for absolutely everything something will jump out and bite ya!
Yep I've also been known to tap on a nasty cage drivers window and request that they stay well away from my behind, ah behind me while travelling I mean't.

[McJim]

People will ride the way they ride. Wanking on about it on a forum isn't going to make anyone sensible.

the only way you can make an idiot sensible is by letting him have a near miss unfortunately.

I think it's known as Gene-O-Kleen (TM)

[James Deuce]

People will ride the way they ride. Wanking on about it on a forum isn't going to make anyone sensible.

the only way you can make an idiot sensible is by letting him have a near miss unfortunately.

I think it's known as Gene-O-Kleen (TM)

Near miss isn't enough. The only thing that works is permanent injury and even then "sensible" doesn't last forever.