*** wouldn't let me on to the m50!

Balfa

Alun wrote: »

If we're talking about a slip road, it's a different can of worms altogether though.

I agree with everything you said except this. What's so different? I guess the right of way rules are slightly different, but the pattern for optimum traffic flow is identical. It's still two strings of traffic becoming one.

R.O.R

I get on the M50 Northbound everyday at Ballymount, usually just before 6.

Last night I entered the M50 doing just under 100km/h at about 5.50pm - based on the volumes of traffic I'd be surprised if it was heavy at 6.00pm

At Ballymountthere are 2 merges. If you are coming from Belgard Road side there is a Merge with the main slip road, which is traffic coming from Ballymount. I come from Belgard end and try to merge into the main slip as soon as possible. There are a good few people who carry on down this slip as far as possible and try to bully into the main slip when they can go no further.

The next merge is generally one of two ways. Either traffic is qued chokka-block all the way in the inside lane, or it's flowing easily. If it's chokka it a case of trying to get in anywhere, then safely in to the middle or outside lanes as the inside lane becomes the N7 slip road (which is why it's chokka). If the N7 slip isn't bad, I don't think I've ever had to go even half way down the Ballymount slip before matching my speed to the traffic around and safely joining the motorway.

OP - try slowing down a little tonight and going in behind the car that has right of way.

Zube

Alun wrote: »

No need to stop and start ..why should they?

I'm not saying anyone wants to stop and start, I'm saying that that's what happens. Think of the situation where a car is crashed in the motorway hard shoulder (somewhere like the UK or France with a real stretch of motorway, I mean), and traffic slows down to look. What happens in practice? A complete stoppage some distance behind the rubberneckers, as faster traffic slows and fills the carriageways.

Alun

Balfa wrote: »

I agree with everything you said except this. What's so different? I guess the right of way rules are slightly different, but the pattern for optimum traffic flow is identical. It's still two strings of traffic becoming one.

Like you said, the right of way situation is different in as much as traffic on the mainline has priority and merging traffic must yield (although you wouldn't think it most of the time), whereas in the case of the roadworks example there isn't really any clear cut priority either way. Plus a roadworks situation is an exceptional case where traffic is generally moving more slowly than usual, whereas merging traffic on a sliproad is the general case and traffic is generally moving at a normal pace.

bazz26

I think this thread has reached the end of the (slip) road.

Alun

Zube wrote: »

I'm not saying anyone wants to stop and start, I'm saying that that's what happens.

... and I'm saying that it doesn't. Have you ever driven anywhere where zip-merging is the rule? I have, and it works like a dream, believe me.

Think of the situation where a car is crashed in the motorway hard shoulder (somewhere like the UK or France with a real stretch of motorway, I mean), and traffic slows down to look. What happens in practice? A complete stoppage some distance behind the rubberneckers, as faster traffic slows and fills the carriageways.

Totally different situation. There's no merging taking place here, just abject stupidity in both lanes.

Balfa

Zube wrote: »

This really does mean the queue is more likely to stop completely, and a stoppage to ripple back away from the obstruction.

Madness.
First of all, the reason I said people should merge as late as they can given their driving ability was so that there wouldn't be sudden stoppages caused by incompetent merging. There's no reason why it would make the queue more likely to stop completely.
Second of all, I'm sure we can agree that if you have a 100km motorway and close a lane on it for 90km, throughput will be much lower than if you close a lane for 1km. Similarly, if you close a lane for 1.25km, throughput will be lower than if you close it for 1km.
So all your early merging really achieves is to artificially increase the length of the lane closure, and reduce overall road throughput. That's how simple it really is.

If you see a comfortable gap, get into it, but don't hold off moving up five cars to get into an equally comfortable gap just because "it's not your turn".
That's how I approach it, and like I said, there's always a comfortable gap.

Some people come to a complete stop anyway, nowhere near the end of their lane, just because they don't want to be seen "skipping". Madness, I tells ya.

Balfa

Alun wrote: »

Like you said, the right of way situation is different in as much as traffic on the mainline has priority and merging traffic must yield (although you wouldn't think it most of the time), whereas in the case of the roadworks example there isn't really any clear cut priority either way. Plus a roadworks situation is an exceptional case where traffic is generally moving more slowly than usual, whereas merging traffic on a sliproad is the general case and traffic is generally moving at a normal pace.

Certainly the pace of traffic has a major impact on how merging occurs. Much more so than any right of way rules. And you can easily find roadwork lane closures where traffic's moving relatively freely, and sliproads where traffic isn't. So I think it's fairer to approach them solely based on the traffic volume, rather than on the fact that one's because of roadworks and one's because of entering the motorway.

And besides, there's always a clear cut priority, one way or another.

But yeah, I think in we're making the same point in different ways

Zube

Alun wrote: »

Totally different situation. There's no merging taking place here, just abject stupidity in both lanes.

It's not totally different. It's what happens, what physically has to happen, if a steady stream of traffic is suddenly slowed enough, for whatever reason. The road capacity drops suddenly from a free-flow value to a lower, congested value. Traffic arriving at the free-flow rate builds up and must eventually stop, unless there is a system to slow traffic down well before the congested section.

Zip merging will work without stoppages up to a certain traffic level. An earlier gradual merge will work without stoppages up to a higher traffic level, provided drivers are well behaved.

Alun

Zube wrote: »

Zip merging will work without stoppages up to a certain traffic level. An earlier gradual merge will work without stoppages up to a higher traffic level, provided drivers are well behaved.

I'm not suggesting that zip-merging be used when it's clearly not required, i.e. at low traffic densities and higher speeds, there'd be no advantage and it would be silly, but when things get slower and more congested it works a damn sight better than an uncontrolled merge at an unspecified arbitrary point some distance ahead of the roadworks. And if traffic comes to a dead crawl for whatever reason, then zip merging is at least the fairest way to do it, regardless of any speed advantage.

Steve

I think KB posted this link a few months ago in a similar discussion.
It's fun to play with the traffic levels though and see the effects of different speed limits on lane closures etc.

enjoy.

http://www.traffic-simulation.de/

Zube

Balfa wrote: »

Second of all, I'm sure we can agree that if you have a 100km motorway and close a lane on it for 90km, throughput will be much lower than if you close a lane for 1km.

I agree, but it's not as simple as that. Closing 10 metres of one lane will have an enormous effect, disrupting flow and forcing merging, and above a certain traffic level, queueing. 20m will not double the effect. 100m will not multiply it by 5.

Once you get to a very long restriction, the total throughput of the whole motorway section is set by the throughput of the restricted section, and you can close the whole lane without making things worse.

So all your early merging really achieves is to artificially increase the length of the lane closure, and reduce overall road throughput. That's how simple it really is.

It can't improve throughput above the ideal maximum which can get through the bottleneck, obviously, but it can reduce the chances of congestion at the bottleneck. Roads have a much, much lower capacity once they become congested to stop/start levels.

If you see a comfortable gap, get into it, but don't hold off moving up five cars to get into an equally comfortable gap just because "it's not your turn".

I don't disagree with that, what makes the gradual merge superior is that it increases the distance within which traffic finds these comfortable gaps and merges without stoppages.

By queue jumping behaviour I mean someone who always drives right to the cones/end of lane, and then barges in, without looking for one of those comfortable gaps. The queue jumper is very likely to have to stop, and wait for a Good Samaritan idiot to reward his bad behaviour by stopping the other lane, quite possibly switching the flow from free (but slow) to congested stop/start behind.

Balfa

Zube wrote: »

I agree

Yay!

I don't disagree with that

Hooray!

By queue jumping behaviour I mean someone who always drives right to the cones/end of lane, and then barges in

Okay, we pretty much agree in principal, but I just want to make sure you understand that I do leave it relatively late AND I "barge" into gaps that some people might be uncomfortable entering. I'm sure there are some people who see what I do and think I'm being a prack. But everything's relative, and without being able to put an actual distance or time number on it, and understanding that I judge every situation uniquely, you'll have to take my word for it: I'm very comfortable with what I do, and I'm confident it improves traffic flow in general.

Thank you for the discussion.

Wibbler

OP and others, have a play with this traffic simulator:

http://vwisb7.vkw.tu-dresden.de/~treiber/MicroApplet/

It's pretty enlightening.

mcwhirter

easyontheeye wrote: »

:mad: :mad: :mad:

was coming onto the m50 about 6 yesterday evening at ballymount heading northbound. was coming to the end of the cones/bollards trying to squeez into the lane, this woman, english reg focus sped up to block me...yes sped up!!!! the traffic was only moving at 5/10 mph... so anyway i was gonna basically crash into the cones, so i said <SNIP> this and aggressively pushed in..she backed away screaming abuse!!! ...the traffic is crawling what is her problem...man i went mad! Im very curteous on the road and would never be that <SNIP> as to speed up to block someone off!

if ever i need a punch bag to vent my anger it was then!!!

rant over



caveat:"would never be that <SNIP> as to speed up to block someone off" ... unless its some tosser weaving and bobbing in and out of lanes!

Are you sure it was English reg, not british or ni

Steve

Wibbler wrote: »

OP and others, have a play with this traffic simulator:

http://vwisb7.vkw.tu-dresden.de/~treiber/MicroApplet/

It's pretty enlightening.

Em..

http://www.boards.ie/vbulletin/showpost.php?p=56736948&postcount=72

Wibbler

SteveC wrote: »

Em..

http://www.boards.ie/vbulletin/showpost.php?p=56736948&postcount=72

Sorry, missed your post earlier in the thread.

G-Money

Sounds like a bit of an over-reaction from the other driver, but most of the time someone will let you into the lane, especially when the traffic is barely moving.

I was driving the Mad cow junction last weekend heading on the N7 outbound but the new layout caught me out and I ended up in the wrong lane. I was coming off the M50 northbound so I was on the temporary free flow loop, but hadn't realised I needed to change lanes after exiting the loop so I stayed on the right and ended up in the lane heading for the city I believe. Luckily enough the people behind/beside let me out when they seen I'd the indicator on so it was grand. The only thing that annoyed me was myself for getting in the wrong lane to begin with

There are a lot of ignorant drivers on the road, but I'd prefer them any day of the week to a dangerous driver.

wil

mcwhirter wrote: »

Are you sure it was English reg, not british or ni

They dont tolerate it very well in the UK which is why is doesnt happen there so often.
Far too tolerated here which is why it happens all the time.:(

Truck drivers regularly police this type of idiocy by straddling 2 lanes at once coming up to an obstruction.
It is really frustrating for people driving for a living, following the rules when you have many idiots abusing the system and bullying their way in front of others for their own selfishness and reducing the overall safety of the roads as they barge their way in at the last second.:(

dingding

pvt.joker wrote: »

Or you could have come to a standstill, accepted her for what she was, an ignorant driver, and waited for someone with a bit of decency to let you in. No need for a reaction like yours to be honest.

+1

Not worth the agro.