Rant

JP1978

The thing that generally starts the queues and makes them worse is people changing lanes to the perceievd lane thats going to go faster. Stop it. Just stop it.

When you see the traffic backing up, pick a lane (prefearbly the one your already in) and stick to it.

Car in Lane 3 see's that Lane 2 is moving quicker, they are that desperate to get into 2, they make a last minute lane change, causing all those in 2 to brake and slow down. This now means that L1 will be going quicker so people move into those lanes.

bigadaj

Lane changing can be marginally quicker if following a logical thought. Motorway queuing is typically around busy junctions, people see this and try to move to lane 2 or 3 very early. So intiially lane 1 becomes empty, and you can progress more rapidly in that lane. Approaching teh junction the joining traffic then slow down the inside lane, so moving out to lane 2 and then lane 3 would be better, this does assume someone would leave you in but it's soemthing I sometimes do. More efficient use of roadspace as much as saving me a few seconds.

Robisere

I will never forget coming back from a holiday and driving into a massive tailback on the M40. Almost 50 minutes to go a little over a mile in stifling heat, and the woman in front of me decided to change her make up and rearrange her hair, for 10 minutes before moving. There developed a big gap between her car and the one in front. As the inner lanes were solid, we could not move until she did. Lots of drivers shouting at her, she flipped a finger out of the window of her BMW. The guy behind me got out, walked up to her car, reached into her open window, grabbed her lipstick and wiped it across her forehead. "MOVE! Or I'll make you eat it!" She moved.

Not condoning what he did, but I knew exactly how he felt!

AndyPix

To all the advocators of leaving stupidly big gaps, and thier notion that it makes no difference to the rest of traffic behind ..


By your logic, i should get in the 3rd lane, stop dead, and not move until ALL the traffic has completely gone from the motorway, thus allowing me to drive to work without stopping once, and allowing "smooth flow" of traffic ..


You see the flaw in that ? There has to be a "cut-off point".
I would say 2 car lengths - any more than that and its blood eagle time for you .. skip the flogging


https://en.wikipedia.org/wiki/Blood_eagle

JP08

AndyPix wrote: »

To all the advocators of leaving stupidly big gaps, and thier notion that it makes no difference to the rest of traffic behind ..

By your logic, i should get in the 3rd lane, stop dead, and not move until ALL the traffic has completely gone from the motorway, thus allowing me to drive to work without stopping once, and allowing "smooth flow" of traffic ..

You see the flaw in that ? There has to be a "cut-off point".
I would say 2 car lengths - any more than that and its blood eagle time for you .. skip the flogging


https://en.wikipedia.org/wiki/Blood_eagle

Of course you're right here, there's a cut-off. And it's right at the point where the stopper moves and reaches the car in front just as it moves off ...

almillar

I'd rather make my brakes last as long as possible and maximise fuel efficiency because I am tight, so not start/stop if I can avoid it.

This will happen, but that's not even what this is about - it's about everyone getting there faster! The money savings are a by-product.

Totally wrong.
In a queuing motorway your first aim is not to be hit, then not to shunt the car in front of you.
Patience saves injury and lives in any traffic jam situation.
Friend of mine was rear shunted by an impatient smart alec last week who wasn't reading the road ahead.

Driving the way I stated would make being shunted from the rear LESS likely, because you're smoothing out the flow. Sudden stops would increase the risk of rear shunts. I'm assuming people have actually passed their test if they're on the motorway. You should also keep breathing I guess, sorry for not pointing that out.

But I wouldn't say stop/start has any kind of "flow" to it given flow means to move steadily & continuously.

You're trying not to stop. Of course, this is not always possible, but it's the aim. If there is no flow (traffic is stopped) you try to create it - if the cars in front are stopped, then start moving, and you manage to roll along up to them and NOT STOP, you've just created flow for yourself and those behind you. You've just prevented a concertina!

Surely more problems are caused by the drivers which switch from lane 2 to the fast lane because its 6 inches further forward then switch back to the middle lane when it moves faster.

It causes a problem if you cause someone else to brake. If you do it without a proper gap. There's much less (but still some, of course) impact if you change into a big gap.

To all the advocators of leaving stupidly big gaps, and thier notion that it makes no difference to the rest of traffic behind ..

I don't actually think anyone has done that...

By your logic, i should get in the 3rd lane, stop dead,

And certainly the opposite of STOPPING, the advice is to KEEP MOVING if at all possible.

You see the flaw in that ? There has to be a "cut-off point".
I would say 2 car lengths

There you go. 2 car lengths is arguable, I wouldn't want to set a strict distance. I can afford a bigger gap if I'm beside a lorry for example, because he won't pull in on me.

hollie.weimeraner

AndyPix wrote: »

You see the flaw in that ? There has to be a "cut-off point".
I would say 2 car lengths - any more than that and its blood eagle time for you .. skip the flogging

The Overall stopping distance when travelling at 70mph is 315 feet (96 metres).

This is made up of: (thinking distance: 70 ft (21 m)) + (braking distance: 245 ft (75 m))

I have seen the aftermath of major accidents caused by people travelling too close too fast (numerous times) and it really isn't pleasant.

I am not advocating that you leave 96 metre gaps but 2 car lengths at 70 mph is ridiculous. The best rule of thumb is the 2 second gap between yourself and the car in front which is the one advocated by the IAM

NBLondon

er Hollie - the discussion is about slow-moving traffic not at 70mph!


Some years ago I used to commute along the A102 (3 lane dual carriageway)through the Blackwall Tunnel and observed all this sort of behaviour. It would be great if you could roll along slowly and smoothly but as others have said above - leave more than a car length and some idiot will dive into it - or on that particular route a filtering biker will cut across your bows. I did on a few occasions keep an eye on the "lane-change at any opportunity" brigade as they thought they were making progress and the average benefit seemed to be no more than 3 car length. Which might in that case get you through the lights one cycle earlier. Not really worth the risk, I'd say. Chopping and changing might work a bit better on a motorway but again - I'd say not worth the risk of being clipped by a daydreamer or getting into a road rage incident.


Mind you - there are some people who will honk away behind if you haven't moved forward 6 feet as soon as the car in front does.

hollie.weimeraner

NBLondon wrote: »

er Hollie - the discussion is about slow-moving traffic not at 70mph!

That'll teach me to join a conversation at the back of the queue, although the 2 second rule should still apply really as it's applicable at all speeds which is my get out of jail free card!:D

Joe_Horner

NBLondon wrote: »

er Hollie - the discussion is about slow-moving traffic not at 70mph!

Fair point, but 2 car lengths (assuming an average 4.5m long car) is only sufficient gap up to just under 10mph. And that's assuming you're sitting in the stop-start traffic fully alert and concentrating to the same extent you would be in normal traffic. Most people switch off a little bit in a crawl and that massively increases the reaction time.

The ideal gap from a traffic flow perspective is whatever is enough that you reach the "safe distance" behind the stopped cars ahead just as they start to move again while maintaining a steady speed the same as the average traffic flow. So, if the average flow is 10mph you should be closing to 2 car lengths just as they start moving again. At which point they do a mad dash forward, you keep rolling at your steady 10mph, and the gap opens again.

That's so good at maintaining traffic flow that, if everybody did it, you'd virtually eliminate motorway congestion altogether.