A different merge in turn argument.
Discussion
I went out yesterday and traffic was very heavy, there is a stretch of road on the A30 between Chiverton cross roundabout and Carland cross that is often choked up due to it being nearly all single lane both ways.
I was heading from the South west and from Chiverton cross it was queued up all the way to Carland cross.
The traffic was stop start and progress very slow when we were moving.
Roughly halfway between the two roundabouts just after the Nissan Garage on the hill is a section of road with a slow vehicle overtaking lane to enable you to get past trucks and tractors and other vehicles that are slower. This lane is not very long and is obviously just a little overtaking opportunity.
I got to this section and stayed in the left lane, well, it was gridlocked and both lanes were full until the merge point at the top of the hill and progress was slow to the top of the hill, painfully slow.
Once I got past the merge point it amazingly speeded up and although slow we did not stop again.
What was happening was the cars that chose to pop out of line and use the right hand lane were having to re-merge and this was slowing everyone down, the right hand lane seemed to be making better progress than the left lane as people stopped to let others in or were forced to stop by multiple people pushing in.
My take on it is that no-one ought to have been in the right hand lane, everyone was "in traffic" and the use of the overtaking lane just held everyone up even more than the volume of traffic had already done. I think the use of the overtaking lane actually meant the tailback was a lot longer because an unnecessary funnel obstruction had been created.
Even if merge in turn had worked it would still have held traffic up more than if everyone just stayed in line and did not try and get 5 or maybe 10 places further up the line. I know the general consensus is that it is better to use all the road but at what point does it become a selfish two fingers up at other drivers because you gain a few places ?
I was heading from the South west and from Chiverton cross it was queued up all the way to Carland cross.
The traffic was stop start and progress very slow when we were moving.
Roughly halfway between the two roundabouts just after the Nissan Garage on the hill is a section of road with a slow vehicle overtaking lane to enable you to get past trucks and tractors and other vehicles that are slower. This lane is not very long and is obviously just a little overtaking opportunity.
I got to this section and stayed in the left lane, well, it was gridlocked and both lanes were full until the merge point at the top of the hill and progress was slow to the top of the hill, painfully slow.
Once I got past the merge point it amazingly speeded up and although slow we did not stop again.
What was happening was the cars that chose to pop out of line and use the right hand lane were having to re-merge and this was slowing everyone down, the right hand lane seemed to be making better progress than the left lane as people stopped to let others in or were forced to stop by multiple people pushing in.
My take on it is that no-one ought to have been in the right hand lane, everyone was "in traffic" and the use of the overtaking lane just held everyone up even more than the volume of traffic had already done. I think the use of the overtaking lane actually meant the tailback was a lot longer because an unnecessary funnel obstruction had been created.
Even if merge in turn had worked it would still have held traffic up more than if everyone just stayed in line and did not try and get 5 or maybe 10 places further up the line. I know the general consensus is that it is better to use all the road but at what point does it become a selfish two fingers up at other drivers because you gain a few places ?
in your lane scenario...Getragdogleg said:
Even if merge in turn had worked it would still have held traffic up more than if everyone just stayed in line and did not try and get 5 or maybe 10 places further up the line. I know the general consensus is that it is better to use all the road but at what point does it become a selfish two fingers up at other drivers because you gain a few places ?
Only reason it doesn't work is morons with a queuing mentality. Otherwise we all just merge in turn without worrying about it.The only reason it was taking them time to re-merge was idiots in the other lane. Let people get on with making progress however ill informed they may be. It will cost you nothing in the final analysis.
Motorrad said:
Getragdogleg said:
Even if merge in turn had worked it would still have held traffic up more than if everyone just stayed in line and did not try and get 5 or maybe 10 places further up the line. I know the general consensus is that it is better to use all the road but at what point does it become a selfish two fingers up at other drivers because you gain a few places ?
Only reason it doesn't work is morons with a queuing mentality. Otherwise we all just merge in turn without worrying about it.The only reason it was taking them time to re-merge was idiots in the other lane. Let people get on with making progress however ill informed they may be. It will cost you nothing in the final analysis.
No need for those in the left lane to slow or let others in at all. Treat it like a single lane and it would have remained moving at the same pace as the rest of the single lane road after the merge.
My opinion is that those who decided to go out and into the right hand lane were selfish. Nothing to do with "queuing mentality" for those who were happy to remain in the line and everything to do with "smart ass mentality" for those who tried to get a few places ahead of those happy to carry on.
Remember I am NOT talking about merging for roadworks here, I am talking about a short passing lane for getting past slow truck/tractors and the like.
Getragdogleg said:
Treat it like a single lane and it would have remained moving at the same pace as the rest of the single lane road after the merge.
Think about what you're saying. You're saying that speed over the ground is important. When really it's number of cars along road that's important.This is why you will ALWAYS speed up after a merge point:
Say the single lane of road after the merge can support X number of cars per min, which will translate into an average speed of Y mph in this single lane. Before the merge you still have X number of cars per min, you can't have more or less as they all have to go into the single lane, so assuming no huge wasteful gaps the cars per min is the same at all points. However you now have two lanes of traffice, which will therefore translate into an average speed of Y/2 mph in each lane. Hope that makes sense?
I think you're attributing the "slow ground speed" in the two lane section to the process of merging. When actually it's because you're got the same number of cars per min but over twice the lanes so speed in each lane must be half the speed in the one lane section.
Slow but moving would build less tailback though. Totally stopped for 3 or 4 minutes at a time and then move forward a few cars has got to be less efficient use of road than slow steady throughput.
I see what you are saying but this was an odd situation, the traffic was held up by the people using the passing lane and after the merge it all kept moving. if the passing lane had not been there it would never have slowed or stopped.
I see what you are saying but this was an odd situation, the traffic was held up by the people using the passing lane and after the merge it all kept moving. if the passing lane had not been there it would never have slowed or stopped.
Getragdogleg said:
Slow but moving would build less tailback though. Totally stopped for 3 or 4 minutes at a time and then move forward a few cars has got to be less efficient use of road than slow steady throughput.
I see what you are saying but this was an odd situation, the traffic was held up by the people using the passing lane and after the merge it all kept moving. if the passing lane had not been there it would never have slowed or stopped.
Average speed would be unaffected because it's determined by the speed of the single lane after the merge. But yes, some people may have made an advantage, but that's not an argument against merge in turn, in fact it's an argument FOR merge in turn because merge in turn prevents any unfair advantage.I see what you are saying but this was an odd situation, the traffic was held up by the people using the passing lane and after the merge it all kept moving. if the passing lane had not been there it would never have slowed or stopped.
"Slow but moving would build less tailback". This isn't true. The speed at the entry to the two lane section will be the same as the speed at the exit from the two lane section, and the speed IN the two lane section will be 50% (on average) of the single lane sections. The rate at which the tailback grows is determined by the average number of cars moving through the restriction and the average rate of cars using the free flowing road behind. If more are arriving per min than are travelling through per min then it grows, less and it shrinks. Because no one is joining from side roads, or turning off, the average rate of cars per min is the same all through the queue regardless of the number of lanes.
mrmr96 said:
Getragdogleg said:
Slow but moving would build less tailback though. Totally stopped for 3 or 4 minutes at a time and then move forward a few cars has got to be less efficient use of road than slow steady throughput.
I see what you are saying but this was an odd situation, the traffic was held up by the people using the passing lane and after the merge it all kept moving. if the passing lane had not been there it would never have slowed or stopped.
Average speed would be unaffected because it's determined by the speed of the single lane after the merge. But yes, some people may have made an advantage, but that's not an argument against merge in turn, in fact it's an argument FOR merge in turn because merge in turn prevents any unfair advantage.I see what you are saying but this was an odd situation, the traffic was held up by the people using the passing lane and after the merge it all kept moving. if the passing lane had not been there it would never have slowed or stopped.
"Slow but moving would build less tailback". This isn't true. The speed at the entry to the two lane section will be the same as the speed at the exit from the two lane section, and the speed IN the two lane section will be 50% (on average) of the single lane sections. The rate at which the tailback grows is determined by the average number of cars moving through the restriction and the average rate of cars using the free flowing road behind. If more are arriving per min than are travelling through per min then it grows, less and it shrinks. Because no one is joining from side roads, or turning off, the average rate of cars per min is the same all through the queue regardless of the number of lanes.
This is not fluid dynamics, this is people in cars. Merge in turn here would not have been needed if they stayed in lane. the speed on the whole section of road would have been the same and not zero in places.
My problem is the Zero speed part of this. That's a blockage in the drain in fluid dynamics terms.
You could say that about lots of places on the A30 especially further into Cornwall. If noone used lane 2 the queue would be much longer. In my experience its the person in lane 1 sitting 2 inches off the back of the car in front which causes bunching. It would move much quicker if one let one in etc.
nipsips said:
You could say that about lots of places on the A30 especially further into Cornwall. If noone used lane 2 the queue would be much longer. In my experience its the person in lane 1 sitting 2 inches off the back of the car in front which causes bunching. It would move much quicker if one let one in etc.
I know, I live here. The sections where it has been two lanes for a long time and then they go to one are always going to need a sensible approach and merge in turn is the best way. I think at this particular place the traffic should have all kept to lane 1. the queue was longer because it was taking ages to get everyone to merge again. The periods of standstill could have been eliminated.So far no-one has written anything that would alter my mind, I have been involved in the standard merge in turn arguments on here before and have been firmly on the "pro" side of the fence but this is different, this is people causing jams
Johnnytheboy said:
Getragdogleg said:
My opinion is that those who decided to go out and into the right hand lane were selfish.
Don't be daft. If everyone in both lanes left adequate distance for the two lanes to merge, there is no reason why the merge should slow the flow up.I guess what I am saying is that some people unmerged so they could spend some time in a different lane and then re-merge 1/2 a mile later.
Seems stupid to me.
Getragdogleg said:
My opinion is that those who decided to go out and into the right hand lane were selfish. Nothing to do with "queuing mentality" for those who were happy to remain in the line and everything to do with "smart ass mentality" for those who tried to get a few places ahead of those happy to carry on.
Alternatively, they weren't local and therefore didn't realise how short that overtaking lane was? Is there any indication how long this lane is BEFORE you move into it to overtake?When presented with an overtaking opportunity, if you wish to go faster than the vehicles in front it would be ridiculous not to take it. Hardly their fault if it's only about 200m long with nothing to tell you that.
Centurion07 said:
Alternatively, they weren't local and therefore didn't realise how short that overtaking lane was? Is there any indication how long this lane is BEFORE you move into it to overtake?
When presented with an overtaking opportunity, if you wish to go faster than the vehicles in front it would be ridiculous not to take it. Hardly their fault if it's only about 200m long with nothing to tell you that.
I think the "not local" point is why I am not excited or anything about this, I think that a lot didn't realise its only short and that's why they went out there. It was full though, so its not like they saw an overtake opportunity. At the point it starts people just got over to the right and remained there until they had to get back over. When presented with an overtaking opportunity, if you wish to go faster than the vehicles in front it would be ridiculous not to take it. Hardly their fault if it's only about 200m long with nothing to tell you that.
It did seem to flow a bit quicker at one point but I think possibly because I spotted a few cars letting 4, 5 and even 6 cars back in line.
The car that was behind me ended up 2 cars ahead once we got out the other side but he had to shove his way back in and there seemed to be much gesticulating.
The whole thing seemed avoidable and wound lots of people up unnecessarily.
Getragdogleg said:
But they don't do they ? hence the tailbacks and periods of standing still, for everybody in the two lane section.
I guess what I am saying is that some people unmerged so they could spend some time in a different lane and then re-merge 1/2 a mile later.
Seems stupid to me.
https://www.youtube.com/watch?v=-zShHRkwSoII guess what I am saying is that some people unmerged so they could spend some time in a different lane and then re-merge 1/2 a mile later.
Seems stupid to me.
xRIEx said:
Funny video and so true. Thing is, why worry? All this stress because someone got ahead by a few minutes.I have a similar 'merge in turn' when I go into work and there's a guy who comes in stressed every morning about how he wasn't allowed to merge, or someone pushed in and ended up keeping them out and wound down the windows to have a slagging match.
I prefer to arrive 3 minutes later and really not worry about it.
xRIEx said:
I like that !For the record I only travel with a small item of hand luggage !
Every seemingly inexplicable traffic jam on the motorway is caused by people driving too closely, swapping lanes to get miniscule advantages and not letting others change lane. If everyone used lanes properly, was considerate of other motorists and most importantly left a safe and reasonable gap to the vehicle in front, there would never be another phantom stop on the motorway.
It won't work because it only takes one driver to try and gain an advantage on another, to make someone else brake, slow down or change lane and the whole thing crumbles.
In short; people are selfish, greedy, self-centred, self-serving, obnoxious t
ts and the sooner the human race is wiped out by intelligent plants and vegetables, the better.
It won't work because it only takes one driver to try and gain an advantage on another, to make someone else brake, slow down or change lane and the whole thing crumbles.
In short; people are selfish, greedy, self-centred, self-serving, obnoxious t
ts and the sooner the human race is wiped out by intelligent plants and vegetables, the better.Edited by Rawwr on Sunday 24th August 22:14
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