Millennium Line - Broadway Extension: Planning & Pre-Construction

[santak003]

I hear people on this forum say..why replace BRT with a just as slow, longer train (migrant_coconut actually said this a few times). There is an argument for that and it is hard to understand. But I'll try. It requires some explanation. Sorry if it's long, but my communication is not the best no matter how hard I try to condense the concepts down. All of this write up is to refute that replacing LRT with BRT..bus for train..and making no other changes has no benefit..is in fact wrong. The benefit depends on the volume of passengers though. So at some level we should go to light rail segregated vs light rail -- running in traffic.

Well, that is where this document "Light Rail Explained: Better public transport and More public transport" can say it better than me.

The problem with Light rail is that it's benefits are hard to perceive.
Less crowding, less time, more punctionality (aka reliability) are all achieved when switching to a light rail solution and these should be quantified.

Better reliability is the invisible piece that makes light rail the better choice than BRT. A "just as slow" longer train can run less times per hour and is more punctual and has less end to end travel time. This extra reliability has a cost from the customer perspective that should be incorporated.
When I say light rail: I mean LRT it includes skytrain as a fully segregated solution.


"Light Rail Explained: Better public transport and More public transport"
EMTA (European Metropolitan Transport Authorities)
Dr. Rob van der Bijl and
Dr. Niels van Oort
Amsterdam/Delft, June-September 2014
https://www.emta.com/IMG/pdf/light_rail_report.pdf


The argument is as follows:

"The main benefit of transferring the bus line into a light rail line is, next to less direct emissions,
the service can be provided by fewer vehicles than in the case of bus operations. And since
fewer vehicles are needed, the hindrance for crossing traffic (i.e. car and bike traffic) is less,
and more importantly, the probability of bunching of vehicles will decrease. However, the
construction and operation costs of light rail may be higher than bus operations, especially
since Utrecht does not have an extensive rail network that is already available."

and another argument from the same document

"The investigated reference case shows a very poor level of service reliability, which
implies that passengers may have to wait for a second or third bus during a short period
in the rush hour. After the calculation of these passenger impacts, the monetary values of
these effects were calculated, using values of time and values of reliability as shown by
the previous table regarding Actual and expected level of service . The table below shows
the total costs and benefits of the project (Ecorys 2011), showing the substantial contribution
of improved reliability to the positive score of the cost benefit analysis, which is 1.2 (i.e.
the benefits are 20% higher than the costs). The impact of less additional waiting time due
to enhanced service reliability of the light rail line is €123 [million Euros] (calculated over the complete
life cycle) and the reduction of distribution in travel time results in €78 million less societal
costs. So, service reliability related benefits account for 2/3 of the total project benefits
of €336 million [euros].
"

Finally, a source that is often overlooked as part of the reason for the time savings, is the on boarding time savings of the light rail vehicle:

"The main advantage of the new RandstadRail vehicle is the low-level floor. Boarding and
alighting is much easier, especially for the elderly and people with trolleys and suitcases.
Figure below shows the standard deviation of the dwell time of all stops in the city before
and after the transformation to RandstadRail.
For most stops the standard deviation decreased. Table below shows that the standard
deviation is reduced from 20 to 7s. The average dwell time is improved from 28 to 24s.
per stop. This enables more reliable operations with a higher level of service.
Average dwell time Average standard deviation
Tram 28 s. 20 s.
RandstadRail 24 s. 7 s"

So there is the vehicle, but also is the control philosophy (interesting word!) mindset and changes to make the system more reliable.
This is operational excellence applied to drivers to get better reliability:

"The goal of the control philosophy is to improve the level of reliability by decreasing the
distribution in driving times and improving the punctuality. Figure 4.2 below shows the
15th and 85th value of driving times of tram line 6 before and after the application. As
predicted, the distribution of deviation has decreased. In addition, punctuality has improved:
the deviation is decreased and negative delays are almost disappeared."

And also the ROW enhanced and traffic signal priority used:

"To achieve a high quality of service, stopping at locations other than the stops must be
avoided as much as possible. Infrastructure is reconstructed for RandstadRail: own right
of way and priority at intersections is applied. Table below shows the average total delay
per trip before and after the introduction of RandstadRail on the same route. The average
value of delay has decreased and the standard deviation is also smaller, enabling a
higher level of reliability.
Average total delays Standard deviation
Tram 90 s. 60 s.
RandstadRail 20 s. 30 s.
25
TABLE 4.1 – Average Stopping Time Tram and RandstadRail"





To summarize: Unbelievably, just having more doors and a level floor can be a benefit in a business case for light rail.
The reliability and "time saved" are quantifiable and the amounts quantifiable are in the 100's of millions of dollars when switching to a more reliable service.
Now, using the same argument, one could figure out exactly where on the scale of light rail we need to be: above ground with at grade crossing, or underground. Skytrain vs lrt vs brt. This document
is the missing piec for rail arguments.

Basically service reliability impacts not understood and not quantified is the main failure of understanding the benefits of light rail

From the same document, they quantify how much time costs in terms of reliability and cost in euros. Using this they create a benefit for reliability that runs to 100's of millions of dollars for a university that has the same scale of employment and student numbers as UBC and recommend complete segregation:

"To support the CBA with insights in the passenger impacts of service reliability, we
analysed the actual (2008) performance, which we used as the base for the 2020
predictions. In the reference case, the level of service will be very low due to high
passenger demand and insufficient bus infrastructure. In case of the light rail line,
sufficient infrastructure is provided and light rail services require fewer vehicles
thereby reducing the probability of bunching.




Travel purpose Value of time Value of reliability
Business € 10.00 € 14.00
Commuter € 17.44 € 24.42
Other € 6.33 € 8.86
"


Who is the EMTA?: Basically it promotes (important word here: Technical) exchanges amongst many different European Cities (Amsterdam, Paris, Lyon, Prague, Badapest, Montreal, London , Oslo...etc...etc..are all members!)

Because Europe has organizations like these, we see more light rail in Europe: (Think skytrain).
The EMTA is the best of European minds coming together and offering technical guidance to various tranport operating agencies around the world.
In their book, they explain "Why Lightrail?" better than me, but it comes down to performance factors: reliability (and cost in terms of customer retention and time).
And they put a price to it and actually use it to pick light rail over BRT (think skytrain) by using this price.
And..to top it off, they have an explanation as to how to make our skytrain argument even stronger using a real world example that couldn't possibly be closer to our actual real world problem.
That's a crazy coincidence!
"Light Rail Explained" https://www.emta.com/IMG/pdf/light_rail_report.pdf

[santak003]

Originally Posted by Migrant_Coconut

The opposite, actually - with TSP we'd have to push back the 99 to every four minutes, or the streets become a conveyor belt of buses.
If you're thinking of the King streetcar, you'll note that the new traffic rules that enable two-minute frequency also make it effectively impossible to drive on King for more than a couple blocks; neither Broadway nor 10th have that luxury.

Your research appears to be incomplete: the 98 ran every five to seven minutes, which furthers McElhanney's point much more than yours. I'd be very interested in learning of a transit line that does two-minute frequencies with no road closures, only two lanes, and no grade-separation - just TSP.

Translink and I disagree with you. I mentioned before that I read several papers about TSP and it's an old field. There are useful simulators that everyone uses and in fact reliability is a very important factor for all transportation operators like translink (that is my understanding).:

Translink (as of 2020) is now putting up reliability metrics. Reliability is the missing piece in many arguments about transit. It can be quantified. From their bus reliability whitepaper they post what I found out about TSP after a few hours of reading on the internet.
https://www.translink.ca/Plans-and-Proje...t-Network/Bus-Speed-and-Reliability.aspx
https://www.translink.ca/-/media/Documen...0714387EE00B4800D0EA858C5EF5495C5955A4C7


+ Travel time reduction
of up to 18%
RELIABILITY
+ Decreases delay at
single intersections by
up to 80%
+ Travel time variability
reduced by up to 40%
− General traffic delay
may increase slightly by
up to 2.5%
CUSTOMER EXPERIENCE
+ Increases travel
speeds of up to 40%
+ Fewer delays at
intersections
SAFETY
+ Fewer conflicts at
intersections
− New signals may be
confusing to drivers or
pedestrians

Originally Posted by Migrant_Coconut

The cost difference between BRT/LRT/RRT may be linear, but the capacity difference is exponential, as is demand.

It is not exponential capacity for the same stops. The overall design will add scaling, but for the same stops, segregated vs non-segregated...it is not exponential.

Originally Posted by Migrant_Coconut

TSP can't be used for 99 frequencies (as above) and only saves you a few minutes' travel time, we can't expand the trams past three-car layouts, and reliability isn't any better than the 99; being generous, we'd get at most ten, twenty years out of the tram before we had to take it down. And there's a good chance that both construction costs and demolition costs could've paid for the SkyTrain that we'd have to build anyway. Unlike buses, trams are meant to be permanent.

This is super easy for someone to simulate and see and my understanding of the documents out there suggest it is possible with limited side street impacts. This is an argument to go a three car train btw. Since boarding time for wheelchairs and having 4-5 times as many doors and level floors and less time looking for a seat..all add up to large time savings where you don't have to run as frequent. At some frequency, segregation is required, but this is very easy to test in a mature industry. But first an accurate model that other industry players are using would be beneficial since it doesn't cost that much.

Originally Posted by Migrant_Coconut

I'd be very wary of over-relying on technology to compensate for a flawed design. Ask Boeing how that turned out.

I'd agree with you that the risk is there. The cost for segregation is there as well. The ability to quantify the risk does not cost that much. Reliability is the missing piece in the argument.

[santak003]

Originally Posted by scryer

I'm also assuming that it would be electrified based on the Arbutus studies .

Speaking on volume, I think that micmiko had a very good idea of extending the 50 to Main Street Science World station in an attempt to gather more transit data on the route similar to the Arbutus streetcar. Speaking of which, I know that I have been derailing this discussion towards the Arbutus Streetcar proposal (in contrast to LRT being chosen to serve UBC) so I just wanted to remind everyone (and myself) that we already have a thread dedicated towards discussing all of the Arbutus Greenway and Future Streetcar Proposal details. I'll see you there .

Hey scryer. Sorry about the double..triple posts, but I struggle with communications sometimes. I read a hundred documents..and then have to explain them as succinctly as I can. I agree with most of your last post, but for measuring this volume I'm not sure it's so accurate. A light rail is more reliable (or should be) and for that reason there is uptake on it as well. I agree with the sentiment of measuring, but a bus is not appropriate measurement for a number of reasons to do with psychology. The reliability of light rail is underestimated. It can also run more frequently than the 50 and be more punctual and can deal with crush volumes better. If we do non-segregated light rail...it better be reliable....and that means all aspects of reliability. The average transfers per trip in Vancouver is 1.65. That is because people will only take one bus..but will take rail based transit as well, but ask them to take 2 buses and it's too much (because of reliability).

50 is just another bus..and people won't go to it I don't think. It's not apples to apples. It's not just outside with great wayfinding either. Light rail..would be something special..not just another bus.

Also, statistics should be captured for all bus lines throughout the year. Including time spent at intersections and time spent at stops. This helps quantify reliability. Traffic Signal Priority systems throughout the world choose standard setups that contain reliability metrics built in..so even if the bus is not using the priority, you can still capture the metrics. This is a best practice.


"
They found “that the tram is preferred over bus in the three major tram cities in
the Netherlands (Amsterdam, Rotterdam and The Hague) but that the extent of these
preference differences varies among these cities”. Their investigation illustrated that in
case of a rail system up to 10% more passengers are to be expected, compared to a bus
system, having similar quality characteristics (such as frequency, speed and reliability)."





"Another aspect, that is often missing or underestimated is the reduction of crowding due
to the introduction of (light)rail systems. This may be the effect of additional vehicle
capacity and/or increased service reliability. Haywood and Koning (2011) show an
example of public transport passengers in Paris who are willing to travel 8 minutes
longer in case of less crowded vehicles. The main shortcoming however in most light rail
CBAs is neglecting the impacts of increased service reliability, as also mentioned by
Knowles and Ferbrache (2014).
"


https://www.emta.com/IMG/pdf/light_rail_report.pdf
Dr. Rob van der Bijl and
Dr. Niels van Oort
Amsterdam/Delft, June-September 2014
"Light Rail Explained"
European Metropolitan Transport Authority

[santak003]

Originally Posted by red-paladin

Sorry for my absence, I've been in the hospital a while.
Let's please keep this thread on topic.

Hope you're feeling better.

Hopefully it's not me making all the topics go awry. I'm trying to see where I stand on light rail to UBC (segregated, non -segregated). I don't know that much, so it's a bit hard to figure out what's what. Is that off-topic?

[Migrant_Coconut]

Originally Posted by santak003

Translink and I disagree with you. I mentioned before that I read several papers about TSP and it's an old field. There are useful simulators that everyone uses and in fact reliability is a very important factor for all transportation operators like translink (that is my understanding).:

Translink (as of 2020) is now putting up reliability metrics. Reliability is the missing piece in many arguments about transit. It can be quantified. From their bus reliability whitepaper they post what I found out about TSP after a few hours of reading on the internet.

You're missing the point: it's better for bus flow, but worse for everybody else. Again, five to fifteen-minute headways like in TransLink's study, no problem. Every two minutes? Not going to work.

A reminder that what's good for a bus isn't always good for a tram. The bus can detour around the occasional accident or stalled vehicle up ahead, but a tram has to sit there until it's cleared up; not hard data, but nevertheless a hit to reliability.

Originally Posted by santak003

It is not exponential capacity for the same stops. The overall design will add scaling, but for the same stops, segregated vs non-segregated...it is not exponential.

Fully upgraded, BRT = 3,000, LRT = 7,000,* RRT = 25,000. Pretty exponential to me.

*As Rico mentioned, the studies point out that ~7,000 pphpd is max capacity before it starts negatively impacting cross traffic.

Originally Posted by santak003

This is super easy for someone to simulate and see and my understanding of the documents out there suggest it is possible with limited side street impacts. This is an argument to go a three car train btw. Since boarding time for wheelchairs and having 4-5 times as many doors and level floors and less time looking for a seat..all add up to large time savings where you don't have to run as frequent. At some frequency, segregation is required, but this is very easy to test in a mature industry. But first an accurate model that other industry players are using would be beneficial since it doesn't cost that much.

Not sure how Toronto likes it, but most Vancouverites consider low frequency to be a bug, not a feature. Waiting 🞵🞵🞵🞵🞵.

Originally Posted by santak003

Hey scryer. Sorry about the double..triple posts, but I struggle with communications sometimes. I read a hundred documents..and then have to explain them as succinctly as I can. I agree with most of your last post, but for measuring this volume I'm not sure it's so accurate. A light rail is more reliable (or should be) and for that reason there is uptake on it as well. I agree with the sentiment of measuring, but a bus is not appropriate measurement for a number of reasons to do with psychology. The reliability of light rail is underestimated. It can also run more frequently than the 50 and be more punctual and can deal with crush volumes better. If we do non-segregated light rail...it better be reliable....and that means all aspects of reliability. The average transfers per trip in Vancouver is 1.65. That is because people will only take one bus..but will take rail based transit as well, but ask them to take 2 buses and it's too much (because of reliability).

50 is just another bus..and people won't go to it I don't think. It's not apples to apples. It's not just outside with great wayfinding either. Light rail..would be something special..not just another bus.

The "prettiness" of a transit mode is a selling point, but more for tourists and fair-weather riders, not regular riders or drivers wanting to switch.

For most passengers, speed, reliability and frequency matter a whole lot more. One of my current commutes involved a bus, a SeaBus, and two more buses; I've wished for less traffic or more frequent buses, but not once have I wished for a tram all the way there.

[Changing City]

Let's review a few factors (comparing surface Light Rail to SkyTrain tunelled as a continuation from Arbutus, at least as far as the edge of the city).

Is it a continuation of the line that's about to be built? - No, its a different technology that creates the need for a transfer, a different set of rolling stock and its own maintenance and storage facility.

Is it faster than SkyTrain? No, it's slower

Does it carry more people than SkyTrain? No, fewer. And there's no way to increase capacity after a certain point - you just have to waste that investment and hope the money is available to build SkyTrain, which may not be the case for many, many years.

Is it cheaper to operate than SkyTrain? No, it requires drivers

Is it less disruptive than Skytrain? No, it would seriously change the street, remove parking and limit the possibility of widening sidewalks as well as interrupting north/south traffic flows, and potentially block an intersection whenever there's any sort of significant incident

Is it cheaper to build than Skytrain? It should be a bit cheaper as there's no tunneling, but services still have to be moved, and track and platforms constructed. And it needs storage and service facility somewhere on the line

Why would anyone prefer it to SkyTrain? It's less likely to encourage high density development at the station nodes, so there will be less redevelopment overall and less change (except for on the route itself). People who don't like change, or growth don't like SkyTrain. It's Big City transportation. Some people want it to remain West Point Grey Village. Some people prefer slow transit to rapid transit, (or no transit at all, except buses).

[Migrant_Coconut]

Originally Posted by Changing City

Why would anyone prefer it to SkyTrain? It's less likely to encourage high density development at the station nodes, so there will be less redevelopment overall and less change (except for on the route itself).

And even that is pretty debatable. I know we're beating the horse's skeleton at this point, but for anybody else new to the conversation, nothing prevents light rail from "causing" expensive towers at the station nodes (intended for Surrey last election), or a metro from "causing" missing middle housing all around the corridor (intended for Cambie right now). Development is entirely City Council's job, not TransLink's.

[Changing City]

Originally Posted by Migrant_Coconut

And even that is pretty debatable. I know we're beating the horse's skeleton at this point, but for anybody else new to the conversation, nothing prevents light rail from "causing" expensive towers at the station nodes (intended for Surrey last election), or a metro from "causing" missing middle housing all around the corridor (intended for Cambie right now). Development is entirely City Council's job, not TransLink's.

Absolutely. I should have clarified that some of the people who oppose the idea of extending SkyTrain do so because they believe it represents a threat of more towers and greater change. As we know from the existing lines, and stations like 29th Avenue, there might be minimal change. Brentwood on West Broadway is not inevitable (or very likely, really).

[santak003]

Originally Posted by Migrant_Coconut

The opposite, actually - with TSP we'd have to push back the 99 to every four minutes, or the streets become a conveyor belt of buses.

From here to the end of this comment I'm disputing this claim (that has no statistics to support it). The math says you are not right. It's an old industry (Traffic Control) and there is math for that.

Here I go again with my "comment bunching". Who cares about bus bunching, when you get "comment bunching". Well, the thing is that understanding bus bunching is all you have to do to understand what I'm saying next. I'll try and explain it as succinctly as I can, but my perception of the problem is not the same as yours. I disagree with the statement above:

1. This statement seems not to jive with any of the operational research or any of the university research on the topic. It is simple math and what you are saying does not agree with "serious" bus operations. TSP improves the situation for the buses with limited side effects. Translink is recommending it and is not saying "look out for streets like Broadway".

2. From the slowest stop, you can calculate your mean variance and how far apart the buses are moving at the slowest time of day and how long it takes to board the buses. (By doing this for the busiest hour for each stop as a minimum ). This stop is limiting your throughput at that time. 15 minute intervals should be used. Using this probability theory, and by not using Traffic Signal Priority you can get something like this:



With a mean dwell time of 30 seconds and running at 5% failure rate (so bus bunching 1 out of 20 arrivals --- as running at 10% failure can result in operational queuing of buses so 5% is used) and with no traffic signal priority means you CAN run 31 buses an hour. That's the math. It's that simple. It's probability with queuing theory.




" Approximate Capacity of Single Berth, with Queuing Area
Green/cycle time =0.5 [no traffic signal priority]
(vehicles per hour)"


"
High Coefficient of Variation of loading time 80%
High Coefficient of Variation of bus arrival times (not punctual) 80%
5% failure rate for bus bunching: 31 vehicles per hour
10% failure rate for bus bunching: 38 vehicles per hour
20% failure rate for bus bunching: 56 vehicles per hour"



Public Transport Capacity Analysis Procedures for Developing Cities
Jack Reilly and Herbert Levinson
September 2011
http://documents1.worldbank.org/curated/.../697190ESW0P1170d0Quality0of0Service.doc


That is precisely why I went to see what the Operations were doing. The mathematics requires some probability theory understanding, but conceptually you are limited by your slowest stop and you can measure the arrival time of buses and the loading time at each stop..and that is all you need to develop your throughput. You can't do better than this one stop that is slowing you down. (multiple berths would be next before multiple lanes btw). Using this data and allowing for 5% bus bunching you can maintain 2 minute headways without TSP for various dwell times. If dwell times change a lot or have higher variance (like wheelchair loading on a bus vs a tram), you cannot maintain this headway, even if traffic is moving well. It is hard to understand maybe, but that is the theory of it. Using this theory, you can predict your headway...without Traffic Signal Priority. And more importantly, you can compare to your real time results which you should be capturing as part of implementing your traffic signal priority and the gps tracking of movements across your bus stops.

2 minute headways are achievable based on the mathematics without TSP and high variations of arriving buses (within a probability band) With TSP, it only gets better with limited side effects. By limiting the red light time with simple TSP..you will achieve significant help, with little side effects and an overall throughput increase. Translink is looking to do this according to their recent documentation and they mention the side effects as 2% which is the research I've been reading as well which I have mentioned before.

"+ Travel time reduction
of up to 18%
RELIABILITY
+ Decreases delay at
single intersections by
up to 80%
+ Travel time variability
reduced by up to 40%
− General traffic delay
may increase slightly by
up to 2.5%"



My understanding of the topic goes further and I was reading that if you know what you are doing operationally, you can sustain 2 minute headways with no variance: If you have operational excellence (a good control philosophy for dwell time and for traffic signal prioritization) you can sustain 2 minute headways with no variance. Obviously having your own lane would be nice, but it is not required. Having a place where buses could queue at a stop is the next step for throughput.

When you implement TSP, it is always to improve from non-TSP. That includes all cross-traffic. So by implementing TSP, you are improving. The way you make it sound is the reverse and this is not the understanding of the practice. As I previously mentioned, there was survey done in 2010 for TSP in use and every agency using it, favoured it. Basically, you should measure every stop and your weakest link becomes a problem. So it can be headway variance of the stop or it can be dwell time variance of the stop. You can measure this for your specific case. So you have to understand the theory of it..as well as the practice. As I mentioned before, TSP does have impact to cross traffic, but every study out there where they did a before an after, found it to be about 2%. Translink has come out and said the same and has said that it needs our municipalities help implement various reliability measures including active prioritization of signals.

There is a standard modelling tool called VISSIM in the industry for trying out various TSP scenarios using real time data capture. There is standard data collection of TSP as well..and also lots of help in the industry for calculating your reliability and comparing before and after changes for the same days/direction of travel/routes/seasons etc in both simulated and real environments.

Also, BRT is the first stage before moving to LRT...(whether segregated or not). So you have to build the operational excellence (which is there for skytrain) into the BRT stack..and then port it over to segregated or non-segregated light rail operations. By having TSP in the first place, you can measure your reliability and become familiar with what it takes to run light rail (as skytrain operations knows, but maybe the bus operations minus BRT do not).

Translink knows what I'm talking about here as they have just put a document supporting reliability:

Here are the benefits and costs of Traffic Signal Priority according to Translink:

BENEFITS AND COSTS
TRAVEL TIME
+ Travel time reduction
of up to 18%
RELIABILITY
+ Decreases delay at
single intersections by
up to 80%
+ Travel time variability
reduced by up to 40%
− General traffic delay
may increase slightly by
up to 2.5%
CUSTOMER EXPERIENCE
+ Increases travel
speeds of up to 40%
+ Fewer delays at
intersections
SAFETY
+ Fewer conflicts at
intersections
− New signals may be
confusing to drivers or
pedestrians

https://www.translink.ca/Plans-and-Proje...t-Network/Bus-Speed-and-Reliability.aspx

[Migrant_Coconut]

One more time: by "conveyor belt," I'm not saying TSP decreases bus efficiency and causes bunching, I'm saying that TSP increases bus efficiency but makes the road less usable for everybody else.

You keep bringing up the need to use other cities in other parts of the world as benchmarks, but absolutely none of them have ever run a model - much less a pilot program - for two-minute TSP frequencies on a shared road. There's no precedent and no numbers for anything except four minutes or more, which obviously has less pronounced effects on the street.

[santak003]

Originally Posted by Migrant_Coconut

You're missing the point: it's better for bus flow, but worse for everybody else. Again, five to fifteen-minute headways like in TransLink's study, no problem. Every two minutes? Not going to work.

That disagrees with the simple mathematics of the problem and with practice. I'm not saying to do it, but I'm saying that operationally it is not that difficult to maintain. Skytrain maintains their headways and has a reliability to it. Traffic Signal Priority can help, but is not necessarily required. Best practice is to implement it and measure and get comfortable with trying to improve it. Then you move to LRT with real data and real exectations and real experience. Not common sense, but rather, real data supporting operational common sense.

A reminder that what's good for a bus isn't always good for a tram. The bus can detour around the occasional accident or stalled vehicle up ahead, but a tram has to sit there until it's cleared up; not hard data, but nevertheless a hit to reliability.

Originally Posted by Migrant_Coconut

Fully upgraded, BRT = 3,000, LRT = 7,000,* RRT = 25,000. Pretty exponential to me.

*As Rico mentioned, the studies point out that ~7,000 pphpd is max capacity before it starts negatively impacting cross traffic.

Except those numbers are not based on operational excellence. Also, they are not much of an exponent. BRT should be 10,000 and RRT as it relates to segregated operations..is 25,000 and LRT is in between. So not exponential, but it depends on the starting point.

It is not only low frequency that 🞵🞵🞵🞵🞵..it is not sure if you are making your next transfer. So with more transfers..you always want more frequency and punctuality (no bunching). If you know something is going to be there on time..and get there with definitive timing..you will take it more. This is quantifiable.

For example 99 bline has 2-3 times people are waiting for bus. This occurs because of traffic and long dwell times causing bunching..which causes the slow bus picking up everything to slow down even more as the bus is already crowded. So by preventing the slowest point everywhere in the system..and forcing this down as a philosophy of operational practice..you get much better throughput. Now you are ready for LRT discussions of segregation, but first you have to join the philosophy of reliability, which forces a discipline of practice for the drivers and the control center and leads to a better understanding of your current network system. You need this for LRT operations.

We should not be the ones discussing this. It should be apparent in the studies being done on the LRT already. We are not there and for that reason I support not testing on non-segregated LRT until BRT practice shows that we know how to move volume in traffic first.

The whole LRT vs RRT argument is misleading. 1 billion dollars is a lifetime of a lot of people's work. So we should not be discussing this stuff and people in power making decisions should make it clear that they value people's time.

[Migrant_Coconut]

Originally Posted by santak003

That disagrees with the simple mathematics of the problem and with practice. I'm not saying to do it, but I'm saying that operationally it is not that difficult to maintain. Skytrain maintains their headways and has a reliability to it. Traffic Signal Priority can help, but is not necessarily required. Best practice is to implement it and measure and get comfortable with trying to improve it. Then you move to LRT with real data and real exectations and real experience. Not common sense, but rather, real data supporting operational common sense.

SkyTrain maintains its headways over the street, not on it. Nobody's lining up waiting to cross the viaduct!

If you get to question TransLink's stats, we get to question yours. The only "real experience" for a street-running tram with two-minute headways is King Street, and only because they effectively closed the road to make it work.

EDIT: And I just realized that 2.5% traffic delay applies to parallel traffic, not perpendicular. Nice, you had me going for a couple minutes.

Originally Posted by santak003

Except those numbers are not based on operational excellence. Also, they are not much of an exponent. BRT should be 10,000 and RRT as it relates to segregated operations..is 25,000 and LRT is in between. So not exponential, but it depends on the starting point.

It is not only low frequency that 🞵🞵🞵🞵🞵..it is not sure if you are making your next transfer. So with more transfers..you always want more frequency and punctuality (no bunching). If you know something is going to be there on time..and get there with definitive timing..you will take it more. This is quantifiable.

For example 99 bline has 2-3 times people are waiting for bus. This occurs because of traffic and long dwell times causing bunching..which causes the slow bus picking up everything to slow down even more as the bus is already crowded. So by preventing the slowest point everywhere in the system..and forcing this down as a philosophy of operational practice..you get much better throughput. Now you are ready for LRT discussions of segregation, but first you have to join the philosophy of reliability, which forces a discipline of practice for the drivers and the control center and leads to a better understanding of your current network system. You need this for LRT operations.

We should not be the ones discussing this. It should be apparent in the studies being done on the LRT already. We are not there and for that reason I support not testing on non-segregated LRT until BRT practice shows that we know how to move volume in traffic first.

The whole LRT vs RRT argument is misleading. 1 billion dollars is a lifetime of a lot of people's work. So we should not be discussing this stuff and people in power making decisions should make it clear that they value people's time.

BRT + only two lanes - tunnel = 3,000. LRT + busy urban street = 7,000. You have the right to call in whatever hypothetical numbers you can think of. People familiar with the actual corridor have the right to explain how those numbers don't apply.

In rush hour, you can always depend on the B-Line to show up in five minutes or less... unless of course there's an accident, which would hurt trams much more than the buses. Reliability become even more so when the Arbutus extension opens and Central Broadway traffic becomes irrelevant - and when it does become a problem again, we can likely justify a SkyTrain (if not before). We definitely won't need a solution that's "the same schedule, but slightly more punctual."

It is evident, the powers that be do value people's time. That's why we're building a SkyTrain, which saves much more time than a tram ever could. Your own numbers and TransLink's show that trams with TSP would shave off about six minutes from Arbutus to UBC, while a SkyTrain would do twice that much.

And this entire argument is misleading. TSP, capacity, the actual problem is that surface rapid transit on Broadway is approaching maximum practical optimization, and that calls for grade separation, not slightly more optimization for a billion-plus CAD.

[aberdeen5698]

Originally Posted by santak003

My understanding of the topic goes further and I was reading that if you know what you are doing operationally, you can sustain 2 minute headways with no variance: If you have operational excellence (a good control philosophy for dwell time and for traffic signal prioritization) you can sustain 2 minute headways with no variance.

Even if this were true, it would be expensive (due to all the operators required) and it would trash the throughput on all the north/south streets that cross Broadway and carry a substantial volume of their own transit. It's extremely challenging to give signal priority to high frequency trams running in both directions with uneven block spacing and still maintain adequate windows for cross traffic. And given the propensity of cars and pedestrians to gum up the works, I'm extremely skeptical that those kinds of headways could be maintained with much reliability.

Bunching of trams is worse than bunching of buses because buses have more stops that they're able to skip (a higher number of stops with nobody alighting) in order to recover spacing. Trams have fewer stops and a lot less likelihood of being able to skip one of them, so once a tram is off-schedule it stays that way, affecting everything behind it.

[Migrant_Coconut]

Maybe I'm not being clear: drivers and cyclists on the same street as transit will indeed be mostly unaffected by high frequency TSP. Pedestrians, cyclists and drivers on the cross-streets will have a rough time with two buses or trams passing every two minutes, on top of regular traffic.

[Rico]

Just to be clear since my previous post was not understood the way I was hoping. Signal priority is great. We should have it for every B line, rapid bus and surface rail line. It works and when done well has acceptable impacts on parallel traffic. At a certain point it has impacts on cross traffic and some of this is OK too....as long as that traffic is not other transit (or pedestrian). Remember Broadway likely crosses more bus traffic on its route (Main, Cambie, Granville, Burrard ect) than runs on Broadway.
Translink was kind enough to model this in the original study so we know they can run 7,000pphpd before it starts breaking down on Broadway resulting in reduced reliability and speeds. A note, this is based on the max length in the study that assumed (rightly) the LRVs can't block the Main street intersections. This could be fixed (with enough money) by grade seperation.

[scottN]

Originally Posted by Rico

Just to be clear since my previous post was not understood the way I was hoping. Signal priority is great. We should have it for every B line, rapid bus and surface rail line. It works and when done well has acceptable impacts on parallel traffic. At a certain point it has impacts on cross traffic and some of this is OK too....as long as that traffic is not other transit (or pedestrian). Remember Broadway likely crosses more bus traffic on its route (Main, Cambie, Granville, Burrard ect) than runs on Broadway.
Translink was kind enough to model this in the original study so we know they can run 7,000pphpd before it starts breaking down on Broadway resulting in reduced reliability and speeds. A note, this is based on the max length in the study that assumed (rightly) the LRVs can't block the Main street intersections. This could be fixed (with enough money) by grade seperation.

At this point any consideration of BRT on broadway only applies west of arbutus where traffic is considerably lower than on central broadway. None of the intersections have the same sort of queuing issues as broadway & Cambie though, so I suspect the benefits of signal priority would be lessened.

Also I don't think it's fair to compare the ridership of broadway with the combined ridership of all routes going across it. Transit priority measures at each intersection are independent, so the judgement of whether a transit priority measure is too disruptive to cross traffic should be made on an intersection by intersection basis. Broadway has far higher ridership than the combined ridership of the cross-traffic bus routes at Arbutus, Macdonald, Alma or Wesbrook.

[Reecemartin]

[Deleted]

[aberdeen5698]

Originally Posted by Reecemartin

I think its a weird that in Vancouver we often act like we have these astonishing otherworldly frequencies, and thats certainly true when comparing ourselves to pretty mediocre (if not actively bad) systems like Portland and Seattle, but we really don't beat Toronto through and through on frequency by any means . . .

Toronto has a considerably higher population base to support its transit system. In terms of service per capita I think Vancouver is doing very well.

[Migrant_Coconut]

That's entirely fair, but then that's a reason for Torontonians to want Vancouver frequency to be better, because that's what they're used to. Given everything you've said, they should be less tolerant than we are of TransLink (hypothetically) replacing every 99 bus with half as many trams!

[santak003]

Originally Posted by Migrant_Coconut

One more time: by "conveyor belt," I'm not saying TSP decreases bus efficiency and causes bunching, I'm saying that TSP increases bus efficiency but makes the road less usable for everybody else.

You keep bringing up the need to use other cities in other parts of the world as benchmarks, but absolutely none of them have ever run a model - much less a pilot program - for two-minute TSP frequencies on a shared road. There's no precedent and no numbers for anything except four minutes or more, which obviously has less pronounced effects on the street.

I don't think you are talking from experience. I am certainly not. However, the documents I'm reading online for this very old industry do not agree with you.

Yes, TSP has impacts and Translink is going to be using TSP in select spots and yes there are impacts, but well designed the impacts are negligible (2%) and the throughput of what you are trying to improve increases 40%. So what you are saying is not making sense. We run a 2 minute headway for 99 bline during the busy times. This is nothing magical.


"Agency experience was that about 100 buses per
hour was as many as could be scheduled without
having operational problems"


Typical Bus Lane Operation
 All buses stop at every stop
 Bus stops located every 2-3 blocks
 Capacity generally limited to no more than 100
buses per hour, depending on:
 Dwell time at critical stop
 Right-turn volumes
 Number of loading areas provided


https://ti.org/pdfs/Bus_facility_capacity.pdf
Bus Facility Capacity
Portland State University

Loading Area Capacity Example
 Based on real-world data from San Antonio,
reported in TCRP Digest 38
 Average dwell time = 30 sec
 Coefficient of variation = 53%
 Assume a desired 10% failure rate (downtown)
 g/C ratio = 0.55
 On-line stop
 3 loading areas

42 buses per hour is the capacity of a single loading
area
 This stop has three on-line loading areas
(2.45 effective loading areas)
 42 * 2.45 = 102 buses per hour (round down)
 Agency experience was that about 100 buses per
hour was as many as could be scheduled without
having operational problems



http://documents1.worldbank.org/curated/.../815760WP0Trans00Box379836B00PUBLIC0.pdf

"PUBLIC TRANSPORT CAPACITY ANALYSIS
PROCEDURES FOR DEVELOPING CITIES"


"While the throughput capacity of a bus transit route is usually limited by the
operation at the critical stop, the capacity can also be constrained by traffic
operations at critical intersections."


Right turns can impede traffic. There is lots of details of capacity planning with right turns.
This will be at the critical time of day that you would have to measure this.



Typical Values
of R/Nc * P/Nc: 4, 8, 12, 16, 20, 24
Time Lost per Cycle at 3 Seconds per
Pedestrian for one turning lane : 12 ,24, 36, 48, 60, 72*

R = right turns per hour
Nc = number of cycles per hour
P = pedestrians per hour
Source: Levinson, TCRP Report 90, 2003

Importantly:

"For a 60 second cycle, time loss should not exceed 25% of the cycle time or 15
seconds. In the table anything over 4 R/Nc ratio should prohibit right turning vehicles."


Keep in mind that 4 R/Nc is a lot of right turning vehicles and a lot of pedestrians. During morning rush from Arbutus to UBC...there is likely not that many pedestrians per hour, but could be wrong..and the math indicates that you can have several hundred of them.