Dublin Metrolink - future routes for next Metrolink

Sam Russell

strassenwo!f wrote: »

It would be much better, in my opinion, to do a few simple things with this line. First, change the rules to allow 30 tph along the out-of-centre section. That's simple enough. Second, either come up with a plan to use the St. Stephen's Green siding, or plan to build a very easy spur tramline from Peter Place along Adelaide Road to Wilton Place (or perhaps beyond).

The extension along Adelaide Rd towards GCD makes more sense for trams coming from the Northside. GCD is a huge employment area and journey generator as it connects with the Dart and the PPT trains.

It would take a bit of an orgami trick to get Sandyford trams to do the turn required.

antoinolachtnai

strassenwo!f wrote: »

The piddly levels of car throughput at Dunville Avenue and Stillorgan could well accomodate a tram every 120 seconds.

There is a serious mathematical flaw in your analysis.

30 trams per hour is a tram arriving at the junction on average every sixty seconds, not every 30 seconds.

--- correction - should have read '30 trams per hour is a tram arriving at the junction on average every sixty seconds, not every 30 seconds.' ---

It takes at least 30 seconds for a tram to pass. That means that the junction is going to be closed to rubber-wheeled traffic to allow the tram to pass for around half the time.

Reducing the capacity of the junction at Dunville Avenue and Stillorgan Road and Adelaide Road and Cuffe St by 20 percent or so is going to have a significant impact. It is not something to be taken lightly.

Can you provide some sort of model to us for how this could be done taking into account traffic flows?

Even if this were possible, all that could be achieved by doing this is a 20 percent increase in capacity.

The trams are already full at peak time. So this would only be enough to get us to 2027, assuming a sub 2-percent growth rate.

strassenwo!f

antoinolachtnai wrote: »

There is a serious mathematical flaw in your analysis.

30 trams per hour is a tram arriving at the junction on average every sixty seconds, not every 30 seconds.

Antoin, I don't know where you are getting the 30 second figure. I have certainly never mentioned it.

30 trams per hour equates to a tram arriving at a stop every 120 seconds.

[QUOTE=antoinolachtnai;108137593It takes at least 30 seconds for a tram to pass. That means that the junction is going to be closed to rubber-wheeled traffic to allow the tram to pass for around half the time.[/QUOTE]

No, it doesn't. That's the time some of those rubber-wheeled vehicles can pass. Others can pass when there is no tram.

I am no expert on this, but we are well aware that cities like Berlin, Vienna and other European cities are able to accomodate road traffic across their tram lines, in central areas, while facilitating tram traffic of up to 36 tph.

[QUOTE=antoinolachtnai;108137593Reducing the capacity of the junction at Dunville Avenue and Stillorgan Road and Adelaide Road and Cuffe St by 20 percent or so is going to have a significant impact. It is not something to be taken lightly.[/QUOTE]

The Dunville Avenue issue is straightforward. It is not, by and large, an urgent problem to get from one side of Dunville Avenue to the other, across the LUAS. It's not on a major route to anywhere, so a wait of an extra 30 seconds is not going to change anything.

I don't know enough about the Stillorgan issue, so I'm not going to comment. I've seen the road junction there several times, and I suspect that an extra 30 seconds there isn't going to change things dramatically.

With the junctions at Harcourt Road, Hatch Street and St. Stephen's Green, and into the siding at St. Stephen's Green, all I can currently suggest is better traffic management.

This is why I suggest demolition of the derelict house on the corner of Peter Place, and pretty simple construction of a LUAS line along Adelaide Road, across Leeson Street and into Wilton Place. Possibly to be extended further, towards the Grand Canal area

antoinolachtnai wrote: »

Even if this were possible, all that could be achieved by doing this is a 20 percent increase in capacity.

The trams are already full at peak time. So this would only be enough to get us to 2027, assuming a sub 2-percent growth rate.

You, Antoin, like the poster bk, are not reading posts, by me and others.

It is clear that small changes on the Green Line, and small changes in the city, could deliver a 50% capacity increase on the Green Line, enough to ensure that the Green Line doesn't need to be unnecessarily upgraded, and that the focus can be on delivering quality public transport to the southwest of the city.

salmocab

Extra 30 second waits throughout the day cause tail backs and gridlock. It doesn’t affect the car nearest the lights bit the cars 4 or 5 behind. These in turn slow down more cars and it will keep building through rush hour.

salmocab

Oh and 30 trams an hour means a tram through the junction every 60 seconds

antoinolachtnai

salmocab wrote: »

Oh and 30 trams an hour means a tram through the junction every 60 seconds

Yes, correct.

strassenwo!f

antoinolachtnai wrote: »

There is a serious mathematical flaw in your analysis.

30 trams per hour is a tram arriving at the junction on average every sixty seconds, not every 30 seconds.

Antoin, I don't know where you are getting the 30 second figure. I have certainly never mentioned it.

30 trams per hour equates to a tram arriving at a stop every 120 seconds.

antoinolachtnai wrote: »

It takes at least 30 seconds for a tram to pass. That means that the junction is going to be closed to rubber-wheeled traffic to allow the tram to pass for around half the time.

No, it doesn't. That's the time some of those rubber-wheeled vehicles can pass. Others can pass when there is no tram.

I am no expert on this, but we are well aware that cities like Berlin, Vienna and other European cities are able to accomodate road traffic across their tram lines, in central areas, while facilitating tram traffic of up to 36 tph.

antoinolachtnai wrote: »

Reducing the capacity of the junction at Dunville Avenue and Stillorgan Road and Adelaide Road and Cuffe St by 20 percent or so is going to have a significant impact. It is not something to be taken lightly.

The Dunville Avenue issue is straightforward. It is not, by and large, an urgent problem to get from one side of Dunville Avenue to the other, across the LUAS. It's not on a major route to anywhere, so a wait of an extra 30 seconds is not going to change anything.

I don't know enough about the Stillorgan issue, so I'm not going to comment. I've seen the road junction there several times, and I suspect that an extra 30 seconds there isn't going to change things dramatically.

With the junctions at Harcourt Road, Hatch Street and St. Stephen's Green, and into the siding at St. Stephen's Green, all I can currently suggest is better traffic management.

This is why I suggest demolition of the derelict house on the corner of Peter Place, and pretty simple construction of a LUAS line along Adelaide Road, across Leeson Street and into Wilton Place. Possibly to be extended further, towards the Grand Canal area

antoinolachtnai wrote: »

Even if this were possible, all that could be achieved by doing this is a 20 percent increase in capacity.

The trams are already full at peak time. So this would only be enough to get us to 2027, assuming a sub 2-percent growth rate.

You, Antoin, like the poster bk, are not reading posts, by me and others. And I presume Marno21 will now resign as a moderator, after his outrageous shouting performance yesterday morning.

antoinolachtnai

So which part are you denying?

- That 30 trams per hour is a train reaching every junction every minute on average (30 trams*2 directions /60 minutes)?

Or

- That the Luas, at present, is leaving passengers behind at the peak time?

strassenwo!f

Sam Russell wrote: »

The extension along Adelaide Rd towards GCD makes more sense for trams coming from the Northside. GCD is a huge employment area and journey generator as it connects with the Dart and the PPT trains.

It would take a bit of an orgami trick to get Sandyford trams to do the turn required.

Sam, there's no origami trick required.

There is a derelict building at the corner of Peter Place and Adelaide Road, All you need to do is demolish that building and then it is quite straightforward to build southeastward. I would think the route to Wilton Place is quite simple then.

A route into Wilton Place would be very useful. At peak times it could serve the Baggot Street area, Leeson Street, Burlington Road, Fitzwilliam Square. There could be some merit in a tram line into Wilton Place serving those areas.

But, as I said above, what would you do then? There'd be demand in the evening peak, to get directly from the Baggot Street area to Sandyford and Cherrywood. But would it be enough in the off-peak hours?

antoinolachtnai

Spending 60 million to bring a tram through a very busy area of the city, and then only run it for a few hours a day?

How would you make a business case for it?

strassenwo!f

riddlinrussell wrote: »

Strassenwolf this doesn't address the issue I raised that building 150 million worth of tunnel + Stations wont get you far at all and politically saying "Look we've made a start on the South west!" Without actually impacting on the vast majority of those peoples lives in the medium term and simultaneously inviting comparisons of "Well they could have got the metro all the way to Sandyford but they went for a little nub that just barely reaches the canal" would be a PR nightmare for any political party that implemented it. All the people crowing for a south west metro currently are either being honest about it (greens I think want it but are saying they'd tack on another billion to the price tag to do it?) Or just being disingenuous and calling for it without saying how much extra it will cost.

riddlinussell, I am trying to answer as many questions as I can, and I appreciate that you have shown interest in my posts on this issue.

Your posts have shown a political awareness of which I am probably not capable. I can only show that I consider that it is not necessary to build a metro line to the southwest at this time (based on the figures available, metrolink.ie).

My preference is that it should be built to the southwest, even if it is only a 'nub'. The only comment I can make about this is that any commentator who favours this is in favour of a line which is very much over capacity. Dublin does not need this.
EDIT: Also I should point out that the 'southwest-line' being a success would be contingent on it going far enough to have a major impact on the majority of commuters in the area, I just don't see how the 150m can stretch far enough to have the desired effect, so I'd prefer to see it spent on metro than just put back into another pot and have metro stub out in the city centre. If this metro line is a success then you can bet that there will be a major clamor for a second full line, and if they do it properly they wont be extensions or connectors, fully fledged, separated lines with good interchange.[/QUOTE]

Dats me

Strassenwolf could you provide proof of this unsegregated European tram lines running 36tph, I couldn't find anything online.

strassenwo!f

antoinolachtnai wrote: »

So which part are you denying?

- That 30 trams per hour is a train reaching every junction every minute on average (30 trams*2 directions /60 minutes)?

Or

- That the Luas, at present, is leaving passengers behind at the peak time?

I am not denying anything.

At the moment they're running 19-20 trams per hour northbound from Sandyford in the morning peak. The southbound traffic is quite a bit smaller, perhaps 15 tph. (But I would expect that that last bit will probably have to change once the LUAS actually hits a big population centre on the northside, like Finglas. At the moment the only big northside population areas which it hits is Phibsborough/Cabra, where there are other good options for a rapid journey into the city centre).

And all the northbound trams are full, so a lot of passengers are choosing not to push their way onto the tram but decide to wait for the next one. I've seen it in action, though thankfully I don't have to live it every day.

I fully get that there is a capacity issue on the Green line,but I don't get that an upgrade to a metro is a solution at this stage, or for 3-4 decades, for a line which is capable of doing much more.

The Dunville Avenue and Stillorgan crossings are really not an issue. The tram should be the priority, and if more trams means a bit of a longer wait to cross in your car, then so be it.

strassenwo!f

Dats me wrote: »

Strassenwolf could you provide proof of this unsegregated European tram lines running 36tph, I couldn't find anything online.

Yes, certainly.

For starters, here's an interesting article about tram capacity, and tram throughput:
http://www.lrta.org/TramForward/Topic5TFs.pdf

The article mentions a throughput of 36 tph, but that is what is being done in cities where there are several tram lines competing with each other and sharing a central section. I'm not sure that the writer envisaged a situation like the Green Line in Dublin, where it is the only rapid rail service across a whole swathe of the city between the southside DART and the Red line.

Ideally, you would have competing tramlines along the N11, and through Rathmines and Harold's Cross to points in the southwest, in order to put the above article into the proper context of a city which has developed several tramlines.

But it has been determined that there is no route in the southwest of the city (in the Rathmines direction or the Harold's Cross/Kimmage/Walkinstown direction) which is suitable for a LUAS. It seems that only a metro can serve those areas by rapid rail.

I am not a well-travelled person, but I've been in several cities in Europe where they are currently running well beyond the 20 tph that is currently being done on the Green line. One city which I do know reasonably well is Berlin - though I don't live in Germany - and they run 36 trams per hour, at peak times, along the very central section between Landsberger Allee and Hackescher Markt, with several (perhaps a dozen?) road crossings.

You can find it on Google Earth, and check the tram times on the website.

They're doing 36 tph. Dublin doesn't need to get anywhere near that to significantly ease the problems on the Green Line and deal with the metrolink.ie projections until around the second half of this century.

The first half of this century should be used to serve other parts of the city which can't be served by a LUAS line.

salmocab

strassenwo!f wrote: »

The Dunville Avenue and Stillorgan crossings are really not an issue. The tram should be the priority, and if more trams means a bit of a longer wait to cross in your car, then so be it.

Those crossings would not be a bit of a longer wait though, Dunville can be quite busy anyway and it’s only one way at a time. A tram passing every 60 seconds on average means only a car or two getting through then waiting the guts of 2 minutes for another 2 in the same direction. The locals wouldn’t be able to get out of their parking spaces with the traffic slowed down that much. I used to use that junction regularly and the traffic already blocks the few businesses along side the station slowing the traffic would be a nightmare.

bk

strassenwo!f, very simple, the experts have said no more then 24 TPH is possible along the current configuration. It is right there in the metrolink report. End of story, case closed.

Stopping talking fantasy about 30TPH when the experts involved in actually designing and running trams say that 24 TPH is the max.

Again let me expand the quote from the report, as I left out the second paragraph the proves this:

5.1
Line B (Ranelagh to Sandyford)/Segregation
The existing Luas Green Line is limited to running a maximum of 24 TPH. This limitation is driven by the non-segregated nature of the line and in particular the need for vehicles to stop at at-grade crossings at Dunville Avenue and St Raphaela’s Road.

In order to achieve the increased frequency of services to 30/40 TPH required for Scenarios 1, 2 and 3, it will be necessary to completely segregate the line from any interface with road and pedestrian traffic. This will involve taking steps to remove the at-grade crossings and, in addition, closing an existing signalised junction at the access to Alexandra College.

It is right there in black and white. Maximum capacity of non-segregated is 24TPH. Need fully segregated to get up to 30TPH or greater.

strassenwo!f

Yes, so people need to leave a little earlier to buy their coconut milk in Mortons before meeting the girls for coffee and a knees-up in the Mima coffee shop beside the Beechwood LUAS stop. But all of that is happening outside peak times.

strassenwo!f

Bk, forget the report. As I showed above, other cities are doing 36 tph.

We had this stuff years back from the Department of Transport, when they said they didn't think it was a good idea to build motorway service stations, because they had some crazy idea that they weren't good. Now they've come into line with international practice, and there are service stations on Ireland's motorways.

The same can happen with Dublin's trams. At the moment the limit is 24, but we know that other, bigger cities are doing 36 tph, in very central sections. 30 tph would be enough to see the Green line into the late 2040's before it needs to be upgraded.

And if I'm still around then, I'll probably support the upgrade to a metro.

riddlinrussell

strassenwo!f wrote: »

Bk, forget the report. As I showed above, other cities are doing 36 tph.

We had this stuff years back from the Department of Transport, when they said they didn't think it was a good idea to build motorway service stations, because they had some crazy idea that they weren't good. Now they've come into line with international practice, and there are service stations on Ireland's motorways.

The same can happen with Dublin's trams. At the moment the limit is 24, but we know that other, bigger cities are doing 36 tph, in very central sections. 30 tph would be enough to see the Green line into the late 2040's before it needs to be upgraded.

And if I'm still around then, I'll probably support the upgrade to a metro.

Ok, unfortunately we cannot forget the report as it is the report that determines what actually happens with the Metrolink and saying 'but 36tph in Berlin' will not change that.

I actually don't have any problem with your ideas about increased frequency or their practicality, not my area of expertise (nor is politics btw).

All I want is to know how far you intend to get with the 150 million euro available if you go southwest. Can you reach (and serve) enough people that joe public wont see it as a massive waste of money? Don't forget you will likely have to factor in a turning loop at the end of the stub line, which will eat into the money you've got.

Basically I'm pushing a simple thing here. Once the northern section is done you have 150 million euro to spend. There wont be any more until the metro is at least well under construction or completed and people cry out for more. So with your 150 million get as far out of the city centre as you can while serving as many people as you can.

As far as I (and it would seem most others on here) can see the best way to do that with the available funds is by upgrading the line that was specifically designed to take this upgrade.

When they announce 3/4 billion for Metro 2 I will be right there with you banging on the door to get it running from the southwest, probably curving into the city centre and then taking over the green line extension at broadstone and out (but I digress).

bk

strassenwo!f wrote: »

Bk, forget the report.

Forget the report!!!

What a load of rubbish. You have been quoting the report constantly. Now that I dig a bit deeper and the report done by experts in this area again proves you wrong, you want us to ignore it because it doesn't suit your narrative.

That is frankly outrageous.

salmocab

If the NTA announced a plan to have teleport machines at the end of every street in Dublin he’d be on telling us that the Germans put one in the middle of every street and it’s much better that way.

strassenwo!f

riddlinrussell wrote: »

Ok, unfortunately we cannot forget the report as it is the report that determines what actually happens with the Metrolink and saying 'but 36tph in Berlin' will not change that.

Paragraphs, Russell? It would make it much easier to respond to your posts.

No, we can forget the report. We know that other cities, including Berlin, are doing 36 tph, and they're doing that in central sections of their cities. 30 tph, out of the centre, should be very doable in Dublin.

riddlinrussell wrote: »

I actually don't have any problem with your ideas about increased frequency or their practicality, not my area of expertise (nor is politics btw). All I want is to know how far you intend to get with the 150 million euro available if you go southwest. Can you reach (and serve) enough people that joe public wont see it as a massive waste of money? Don't forget you will likely have to factor in a turning loop at the end of the stub line, which will eat into the money you've got.

Russell, your figure of 150 million euro for the southside part of the metro is totally made up. You have no idea what the southside part would cost, and nor do I.

But I'd be very surprised if you'd get away with tunnelling all the way to Charlemont (from, say, Saint Stephen's Green), and removing the road junctions at Dunville Avenue and Stillorgan, and lengthening all the way to Sandyford, for 150 million euro.

[

riddlinrussell wrote: »

Basically I'm pushing a simple thing here. Once the northern section is done you have 150 million euro to spend. There wont be any more until the metro is at least well under construction or completed and people cry out for more. So with your 150 million get as far out of the city centre as you can while serving as many people as you can. As far as I (and it would seem most others on here) can see the best way to do that with the available funds is by upgrading the line that was specifically designed to take this upgrade.

As I posted above, your figure of 150 million euro is totally arbitrary. A David Drumm figure.

riddlinrussell wrote: »

When they announce 3/4 billion for Metro 2 I will be right there with you banging on the door to get it running from the southwest, probably curving into the city centre and then taking over the green line extension at broadstone and out (but I digress).

In my opinion, metro2 would involve the Green Line, because it's not ready to be upgraded yet. There is plenty more capacity to be gained from the Green Line as an overground tram.

strassenwo!f

bk wrote: »

Forget the report!!!

What a load of rubbish. You have been quoting the report constantly. Now that I dig a bit deeper and the report done by experts in this area again proves you wrong, you want us to ignore it because it doesn't suit your narrative.

That is frankly outrageous.

Yes bk, forget the report.

The report you're quoting doesn't tie in with the data provided on the metrolink.ie website. The metrolink.ie website says that there is a capacity of 8,000 people at 20 trams per hour (broadly the current situation). The report you're quoting - from the DTASS - says that there is a capacity of 8,160 from 24 tph.

Can you see the discrepancy here?

I would presume that the metrolink people are closer to the metro project than the people in the Department of Transport, Sport and whatever. Thus, I'm guessing that their figures are more likely to be correct.

And, we know, that other cities are managing 36 trams per hour in central sections of their their cities.

bk

strassenwo!f wrote: »

The report you're quoting doesn't tie in with the data provided on the metrolink.ie website. The metrolink.ie website says that there is a capacity of 8,000 people at 20 trams per hour (broadly the current situation). The report you're quoting - from the DTASS - says that there is a capacity of 8,160 from 24 tph.

Can you see the discrepancy here?

No it DOES not, more rubbish:

http://www.dttas.ie/press-releases/2017/minister-ross-gives-green-light-%E2%82%AC100m-green-line-project

At the end of the Green Line capacity project the capacity will increase to approximately 8,160 passengers per direction per hour based on 24 trams per hour.

From the Metrolink report:

5.1
Line B (Ranelagh to Sandyford)/Segregation
The existing Luas Green Line is limited to running a maximum of 24 TPH. This limitation is driven by the non-segregated nature of the line and in particular the need for vehicles to stop at at-grade crossings at Dunville Avenue and St Raphaela’s Road.

It literally couldn't be more clear.

Also I took a quick look at your Berlin example and I can easily see you are wrong about that too. Just like you were wrong about Frankfurt and you are wrong about Metrolink. I'll write up why when I have more time. But I'm sure you will ignore that too as it doesn't suit your narative.

But the fact is the experts tell us that the maximum frequency for this line is 24TPH, that is it, end of story.

Dats me

strassenwo!f wrote: »

Yes, certainly.

For starters, here's an interesting article about tram capacity, and tram throughput:
http://www.lrta.org/TramForward/Topic5TFs.pdf

The article mentions a throughput of 36 tph, but that is what is being done in cities where there are several tram lines competing with each other and sharing a central section. I'm not sure that the writer envisaged a situation like the Green Line in Dublin, where it is the only rapid rail service across a whole swathe of the city between the southside DART and the Red line.

Ideally, you would have competing tramlines along the N11, and through Rathmines and Harold's Cross to points in the southwest, in order to put the above article into the proper context of a city which has developed several tramlines.

But it has been determined that there is no route in the southwest of the city (in the Rathmines direction or the Harold's Cross/Kimmage/Walkinstown direction) which is suitable for a LUAS. It seems that only a metro can serve those areas by rapid rail.

I am not a well-travelled person, but I've been in several cities in Europe where they are currently running well beyond the 20 tph that is currently being done on the Green line. One city which I do know reasonably well is Berlin - though I don't live in Germany - and they run 36 trams per hour, at peak times, along the very central section between Landsberger Allee and Hackescher Markt, with several (perhaps a dozen?) road crossings.

You can find it on Google Earth, and check the tram times on the website.

They're doing 36 tph. Dublin doesn't need to get anywhere near that to significantly ease the problems on the Green Line and deal with the metrolink.ie projections until around the second half of this century.

The first half of this century should be used to serve other parts of the city which can't be served by a LUAS line.

When I said proof I wanted actual proof that it is happening, not a pdf saying it's theoretically possible and then you typing out again that it's happening. Show me a link that says it's happening. I can't find anything on it, I don't believe you.

strassenwo!f

Dats me do you want me to do to everything for you?

I'm not your mother.

They're running 36 trams per hour. through central sections of B erlin

salmocab

Dats me wrote: »

When I said proof I wanted actual proof that it is happening, not a pdf saying it's theoretically possible and then you typing out again that it's happening. Show me a link that says it's happening. I can't find anything on it, I don't believe you.

It wouldn’t matter anyway, two cities can’t be compared like that. Berlin isn’t the same design as Dublin doesn’t have identical road layouts and traffic numbers going to the same areas. It’s a pointless comparison.

Dats me

Very fair, even if it was happening you can't compare non-segregated systems very usefully. It also seems as if it very probably isn't even happening in Berlin.

riddlinrussell

strassenwo!f wrote: »

Paragraphs, Russell? It would make it much easier to respond to your posts.

No, we can forget the report. We know that other cities, including Berlin, are doing 36 tph, and they're doing that in central sections of their cities. 30 tph, out of the centre, should be very doable in Dublin.



Russell, your figure of 150 million euro for the southside part of the metro is totally made up. You have no idea what the southside part would cost, and nor do I.

But I'd be very surprised if you'd get away with tunnelling all the way to Charlemont (from, say, Saint Stephen's Green), and removing the road junctions at Dunville Avenue and Stillorgan, and lengthening all the way to Sandyford, for 150 million euro.

[

As I posted above, your figure of 150 million euro is totally arbitrary. A David Drumm figure.



In my opinion, metro2 would involve the Green Line, because it's not ready to be upgraded yet. There is plenty more capacity to be gained from the Green Line as an overground tram.

I apologise for my poor paragraphing.

I also apologise for quoting an inaccurate figure for conversion of the green line to metro, it is actually 134 million euro (Assuming the ideal of a Fully Automated HFV)
see item 6.2 Scenario 2: 60m HFV – Fully Automatic

So again I'll ask you to figure out how far you can get to the southwest with €134 million?

bk

Wow I just looked at the article about Berlin and lots wrong with it:

http://www.lrta.org/TramForward/Topic5TFs.pdf

First of all it isn't about Berlin as you claim, it is about Karlsruhe, so again wrong there.

Also the people writing are a non-profit organisation in the UK looking to promote light rail, which is fantastic of course, more power to them, but it doesn't make them experts and it doesn't mean they can't exaggerate.

Here is the quote you are on about:

A typical situation could be a pedestrian street with six routes operating at 10-minute headway giving 36 double coupled trams per hour each with a capacity of 225.

Note, this is very different to the Luas, this is 6 separate lines that happen to meet in the city center long one or two streets and then diverge again.

The frequency of each of these individual lines is just 10 minutes or 6 TPH. WAY lower then the Luas lines 24 TPH. The Luas Green Line has VASTLY more capacity then any of these individual lines.

There is a world of difference between running a tram at 36TPH along one or two streets slowly and then running at just 6 TPH along their rest of their route versus trying to run a tram at 36TPH along an entire route. They aren't at all comparable.

As the Metrolink report clearly points out, the limitation is at the two at grade junctions at Dunville Avenue, etc. That is no surprise to anyone who follows transport infrastructure. Junctions are what limit the frequency and throughput of any system. It is the same reason why the NTA/Irish Rail wanted to close Merrion Gates and want to close other crossings on the Maynooth line, etc.

24 TPH is a pretty incredible frequency for a single line and really it is at the extreme edge of what can be done with non-segregated junctions. I mean just look at Karlsruhe, their trams run at just a very low 6 TPH!

BTW interestingly they are building a tunnel in Karlsruhe in the city center now:

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

All daily tramlines run during the day on weekdays at ten-minute intervals

Since the 1960s, there have been attempts to build a tramway tunnel in the centre of Karlsruhe to relieve the main shopping street of trams.

......

At the end of 2005 the so-called "combined solution" (Kombilösung) for the Stadtbahn tunnel completed the planning approval process. In December 2008, the Karlsruhe regional council approved the details of the work.[4] The Stadtbahn tunnel has been under construction since 2010.

LOL yet another example of a tram line reaching capacity and being turned into an underground!!