Has the Monorail's Future Finally Arrived?

[quashlo]

Originally Posted by electricron

Yes, and elevated light rail basically equals monorail in those circumstances.

Except that a monorail viaduct won't look or feel anywhere near as oppressive.

Seriously, I invite anyone here to find me a double-track elevated light rail system that can look this clean:

Tama Monorail
http://maps.google.com/maps?ie=UTF8&...95.28,,0,-5.41

Or for what Honolulu could have selected, Okinawa Monorail (YuiRail). Aerial structure is substantially thinner and more open:
http://maps.google.com/maps?ie=UTF8&...,0.004823&z=18

Good luck.
By the way, I really don’t care either way, but there seems to be a lot of misconceptions or prejudice in this thread being pushed as fact. 

[electricron]

Originally Posted by quashlo

Except that a monorail viaduct won't look or feel anywhere near as oppressive.

Seriously, I invite anyone here to find me a double-track elevated light rail system that can look this clean:

Tama Monorail
http://maps.google.com/maps?ie=UTF8&...95.28,,0,-5.41

Or for what Honolulu could have selected, Okinawa Monorail (YuiRail). Aerial structure is substantially thinner and more open:
http://maps.google.com/maps?ie=UTF8&...,0.004823&z=18

Good luck.
By the way, I really don’t care either way, but there seems to be a lot of misconceptions or prejudice in this thread being pushed as fact. 

But neither the Okinawa or Tama monorail have the emergency egress walkway that would be required in America. Add that walkway down the middle, and their structures would look much more bulkier. Look at the DART photos I posted earlier, almost half the width of the guideways is for emergency egress. That's why there are handrails. Next you'll be telling us that emergency egress will never be needed.

And getting back to the OP's point, aerial light rail should be able to fit in any cityscape that monorails can - unless the deciding issue is grades.

[Justin10000]

On top of that, LRT can run in the street. Monorails must always be grade seperated. That is a definitive advantage of LRT over Monorails.

[Cirrus]

Originally Posted by quashlo

And why, oh why, would you ever want to do that? Or are you just scrambling to find anything to bolster your argument? It’s elevated… Passengers will make their way to the platforms underneath the aerial structure. That example you posted from Charlotte looks like a case where they cheaped out

You've answered your own question. You'd want to do it because it's much, much cheaper. Anywhere you could possibly get away with crossing the tracks rather you going up or down a level, you save yourself millions of dollars.

The fact that you treat this blindingly obvious answer sarcastically is illustrative of a common tendency among monorail (and PRT) boosters: You don't actually care about technical details, you just like monorails because you think they're gee whiz kewl. You've made up your mind based on first impressions, and no amount of facts will convince you of anything you don't want to hear. That's fine. You're entitled to like whatever you want to like. Just don't be surprised when nobody makes billion-dollar financial decisions based on your opinion.

Originally Posted by quashlo

How conveniently you forget Chongqing (380,000 pax/day) or Tōkyō Monorail (138,000 pax/day), both single lines, and both beating most of the elevated light rail lines you seem to adore without fail.

Passengers per day is irrelevant to a discussion about capacity. Maximum passengers per hour is the pertinent measure.

[Cirrus]

All right. So let's summarize.

Here is a list of things that partisan monorail boosters claim as benefits but that generally aren't:

• Aesthetics. As the Vancouver SkyTrain example shows, traditional rail can be built that looks very similar to monorail (the reverse is not true). Monorail guideways can be somewhat narrower than light rail guideways, but that advantage is usually (not always) canceled out by monorail's requirement for bulkier stations. Overall, aesthetics is a wash except for in a very narrow capacity niche where low platform light rail isn't possible and thus light rail's less bulky station advantage doesn't apply, resulting in an aesthetic advantage for monorail.
• Cost. Monorails are no less expensive than other comparable elevated options (more so than elevated low-floor light rail, since you can never cross the tracks), and their lack of flexibility means they are much more expensive if you want to try and run them at-grade or in a subway. Overall, cost is a negative for monorails.
• Capacity. Monorail capacity is comparable to elevated/grade-separated light rail with high platforms, slightly higher than elevated/grade-separated light rail with low platforms, but lower than heavy rail metro systems. Overall, monorail doesn't offer any capacity advantage over any other mode, resulting in a wash.
• Automation. Any grade-separated transitway can use automated vehicles. This is a wash.

Now here is a list of the things that MUST be true for monorail to be competitive with light rail. You need ALL the things on this list to be true for monorail simply to break even with light rail:

• You have already decided that your line is going to be 100% elevated regardless of what type of train you ultimately choose.
• Your capacity needs fall in the "medium-heavy" range, high enough to require 100% grade-separation but lower than heavy rail.
• You must not care about interoperability with other existing or planned segments of your transit system, or freight.

Now here is a list of things that can push monorail over the top. If your line meets one or more of these characteristics in addition to all three from the previous list, then monorail is probably your best option:

• You have a specific need to climb grades that are steeper than you can climb with a traditional duorail (but not so steep that monorail can't climb them either).
• You have capacity needs high enough to eliminate low-floor elevated light rail as a viable option, but not so high as to require heavy rail. This is most likely in the 15,000-25,000 pphpd range. At these capacities, monorail offers an aesthetic advantage over elevated light rail and would therefore be preferable.

[mSeattle]

Originally Posted by Cirrus

All right. So let's summarize.

Here is a list of things that partisan monorail boosters claim as benefits but that aren't:

• Aesthetics. 1) Monorail guideways in the US cannot be as narrow as those in China because of requirements for emergency and ADA access. Monorail guideways can still be somewhat narrower than light rail guideways, but that advantage is canceled out by monorail's requirement for bulkier stations. 2) As the Vancouver SkyTrain example shows, traditional rail can be built that looks very similar to monorail (the reverse is not true). Overall, aesthetics is a wash.
• Cost. Monorails are no less expensive than other comparable elevated options (more so actually, since you can never cross the tracks), and their lack of flexibility means they are much more expensive if you want to try and run them at-grade or in a subway. Overall, cost is a negative for monorails.
• Capacity. Monorail capacity is comparable to the capacity of any other grade-separated transit system. This can be a wash or a negative depending on the circumstances, but is never a positive for monorails. It's a negative if you don't need that much capacity, and it's a negative if you need so much capacity that you eliminate the narrower guideways that improve monorail's aesthetics, which would have the effect of moving monorail from "wash" in the aesthetic column to "negative". The best case scenario for monorail regarding capacity is that it's a wash, which only happens for medium-to-heavy (but not very heavy) capacity needs.
• Automation. Any grade-separated transitway can use automated vehicles. This is a wash.

Now here is a list of the things that MUST be true for monorail to be competitive with light rail. You need BOTH the things on this list to be true for monorail simply to break even with light rail:

• You have already decided that your line is going to be 100% elevated regardless of what type of train you ultimately choose.
• Your capacity needs fall in the "medium-heavy" range, high enough to require grade-separation but still low enough for a narrow guideway to be possible.

Now here is a list of things that can push monorail over the top. If your line meets these characteristics, then monorail may very well be your best option:

• Both the things from the previous list are true.
• You have a specific need to climb grades that are steeper than you can climb with a traditional duorail (but not so steep that monorail can't climb them either).

Just want to make sure I get it.

1) You can't cross "over" monorail tracks because they're above you. You cross "under" monorail tracks?

2) Automation is not available or is more dangerous in non-monorail systems that are at grade. Collision, collision-prevention and court costs continue for at-grade rail sites?

[quashlo]

Originally Posted by electricron

But neither the Okinawa or Tama monorail have the emergency egress walkway that would be required in America. Next you'll be telling us that emergency egress will never be needed.

No, it is needed, but it doesn't have to be a walkway. Japan has been running multiple monorail systems of various designs (suspended or straddle) safely in a variety of environments for decades. Emergency egress is handled out the side doors or the emergency door at the ends of the train, which allow passengers to evacuate directly onto a rescue train. The requirement for a walkway is a local American requirement in your context and not a failure of the technology itself.

And getting back to the OP's point, aerial light rail should be able to fit in any cityscape that monorails can - unless the deciding issue is grades.

The smaller aerial structures will allow a monorail to be placed in some situations that a bulkier elevated light rail structure wouldn’t fit. A typical monorail station might be slightly taller than an elevated light rail station, but the vertical clearance is irrelevant anyways—it’s the horizontal clearances that matter. In general this space efficiency is less important in a place like the United States which has plenty of wide boulevards to run transit through, but from the perspective of shadows and bulk, a monorail is still a more attractive solution that produces less impacts to the street beneath it.

Chiba Monorail. The aerial structure is built directly above a pedestrianized creek. An elevated light rail would blanket the creek in shadows, but a monorail works quite nicely in this situation:
http://maps.google.com/maps?f=q&sour...p=12,3.06,,0,0

[quashlo]

Originally Posted by Cirrus

You've answered your own question. You'd want to do it because it's much, much cheaper. Anywhere you could possibly get away with crossing the tracks rather you going up or down a level, you save yourself millions of dollars.

I’m still surprised you and others insist on comparing elevated monorail to at-grade LRT. Apples and oranges, people. Of course anything at-grade will be cheaper than anything elevated. We are talking about situations where the line needs to be fully grade-separated, so any talk about at-grade LRT is frivolous and off-topic. A fully grade-separated corridor like the one proposed for Honolulu would be a candidate project for monorail, not that LYNX example you posted. Nobody in this thread is proposing a monorail alternative to LYNX or other at-grade LRT systems. It’s a proven effective solution for situations where at-grade is out of the question… Where would you put at-grade LRT in Sao Paulo or Chongqing?

Originally Posted by Cirrus

The fact that you treat this blindingly obvious answer sarcastically is illustrative of a common tendency among monorail (and PRT) boosters: You don't actually care about technical details, you just like monorails because you think they're gee whiz kewl. You've made up your mind based on first impressions, and no amount of facts will convince you of anything you don't want to hear. That's fine. You're entitled to like whatever you want to like. Just don't be surprised when nobody makes billion-dollar financial decisions based on your opinion.

I think you need to chill out. It’s clear you have an agenda to disprove the viability of monorail. You seem to come out all guns blazing everytime a monorail thread is posted. I invite you to ride a real-world monorail (take your pick of about 10 systems around Japan), instead of rehashing your prejudices over and over again based on riding one monorail at Disney World.

By the way, if you follow my thread here (http://www.skyscrapercity.com/showth...28904&page=128), you’ll find I’m way more “technical” than you claim me to be and not some “gee whiz kewl” booster. I’m simply a transit planner, and I recognize that monorails have their place, but thanks for labeling me as just some frothing monorail fanboy.

Originally Posted by Cirrus

Passengers per day is irrelevant to a discussion about capacity. Maximum passengers per hour is the pertinent measure.

And just how do you think it gets those kinds of passenger numbers if it doesn’t have high capacity? I was going to spare everyone the gory details, but if you really want me to pull out my calculator…

Chongqing Monorail
158 pax / car × 4 cars per train × 18 tph = 11,376 pphpd

Tōkyō Monorail
100 pax / car × 6 cars per train × 18 tph = 10,800 pphpd

By the way, this is capacity of what is actually operated during the peak, not what the technology is possible of serving. Chongqing Monorail has platforms up to eight-cars long, so they could easily get over 20,000 pphpd simply by running coupled 4-car consists. The frequencies are also conservative, so there is plenty of schedule slack to add more trains. The Tōkyō Monorail is an older implementation, so the interior design is not ideal, which is why it has lower capacity per consist even though it has more cars than the Chongqing monorail.

[Cirrus]

Originally Posted by mSeattle

1) You can't cross "over" monorail tracks because they're above you. You cross "under" monorail tracks?

2) Automation is not available or is more dangerous in non-monorail systems that are at grade. Collision, collision-prevention and court costs continue for at-grade rail sites?

1) No. For this point the fact that monorails are elevated doesn't matter. You can cross over the tracks on elevated light rail stations as long as there's not a hole under the tracks that you'd fall through, but you can't cross over a monorail because the "track" is 3 foot high beam that you'd have to climb over.

2) Automation is not available for ANY system that is not fully grade-separated, and IS available for ANY system that is fully grade-separated. Since light rail and other traditional rail modes can be fully grade-separated if you want them to be, automation can be applied to any type of train and therefore is neither a strength nor a weakness for any of them.

Originally Posted by quashlo

I’m still surprised you and others insist on comparing elevated monorail to at-grade LRT. Apples and oranges, people.

Absolutely not. That difference goes to the very heart of why monorails are used so sparingly. Most transit lines around the world actually operate at mixed grades. The same line will spend part of its route elevated, part underground, and part at-grade. Even most of the so-called "elevated" lines around the world usually have at-grade segments in places. The fact that monorail is not capable of running at-grade without incurring major additional costs is exactly why it is so shunned.

In other words, it is totally fair to compare surface LRT to elevated monorail, because that is often the choice we are faced with when deciding modes. And likewise, it isn't usually fair to compare elevated monorail only to elevated LRT, because almost any elevated LRT line you can design would also have segments operating at-grade.

The sort of mixing between elevated and at-grade you see with the Charlotte light rail is EXACTLY why light rail is usually chosen over monorail. Unlike, say, automation, that flexibility is an inherent advantage that light rail has. If Charlotte had gone with monorail they would have had to elevate miles and miles of sections that they could build at-grade with light rail, at monstrously more expense.

Originally Posted by quashlo

We are talking about situations where the line needs to be fully grade-separated... A fully grade-separated corridor like the one proposed for Honolulu would be a candidate project for monorail

Where have I disagreed with this? If you will review the thread you will find that I have made essentially this exact statement multiple times.

I labeled you a gee whiz kewl booster because you seemed uninterested in my repeated statements that monorail has its place, but that "its place" is limited to situations where you're already planning to be elevated for the whole route anyway. If you don't disagree with that statement then why are we quarreling?

A couple of more things, just for the record:

• 11,000 pphpd is exactly the medium-high capacity range I identified as appropriate for monorail in my last post. Most American at-grade LRT systems that cross streets have less then 5,000, while fully-separated LRT can go up to 20-25,000 (but rarely does). Most third rail metros around the world are in the 30-40,000 range, with a few up to 80,000. 11,000 pphpd is exactly the range where you'd be justified going to the expense of full grade separation, but not enough to need a particularly heavy system. In other words, your numbers show that those two lines fit exactly inside the niche of capacity needs that are appropriate to be served by monorail.
• Honolulu's pre-EIS Alternatives Analysis *did* include monorail. I'm not sure why it wasn't advanced, but it was definitely there in the early study stages.

[quashlo]

Originally Posted by Cirrus

Absolutely not. That difference goes to the very heart of why monorails are used so sparingly. Most transit lines around the world actually operate at mixed grades. The same line will spend part of its route elevated, part underground, and part at-grade.

Compatibility matters when you have an extensive existing urban rail network to speak of. Not the case for many cities in developing countries (e.g., Chongqing). If you want to claim that these new systems are “1% of the time”, go ahead. I don't care.

Originally Posted by Cirrus

I labeled you a gee whiz kewl booster because you seemed uninterested in my repeated statements that monorail has its place, but that "its place" is limited to situations where you're already planning to be elevated for the whole route anyway. If you don't disagree with that statement then why are we quarreling?

Perhaps because you’re irrational aversion to anything monorail-related has led you to make foolish claims that only serve to highlight your ignorance, like the following?

Originally Posted by Cirrus

Oh and by the way, we haven't talked about capacity, but if you want your monorail to have those light-looking support structures that partisan monorail boosters are so enthralled over then you can't have very heavy (ie long) trains, which means you can't even match the capacity of light rail (never mind heavy rail)! In order to get any capacity advantages out of monorail, you need the sort of the heavy elevated structures that are required for every other mode!

Do you have any comment on my rebuttal regarding pphpd for Chongqing and Tōkyō? Or shall I go to Hitachi’s website to pull out some more capacity numbers to convince you?

Or how about about this statement?

, and it would still be true that you could put a pedestrian crossing on an elevated LRT station because the engineering wouldn't look any different.

Again, what transit agency in their right mind would ever want to do this? You go with elevated (i.e., a form of grade-separation) to avoid conflict, not to introduce new conflict. LYNX’s 3rd Street Station was a poor example, as it’s not a “true” elevated station... It’s on an embankment, but not on aerial structure.

Please show me an example of these crossings along elevated light rail stations you seem to think are so common… You will find they are a rarity more than anything, even less than the “1% of situations” you love throwing around with regard to monorail’s applicability.

It’s funny… For the most part you seem a reasonable, intelligent guy (if a DC booster), but when there is a thread about monorail, it just brings out the worst in you.

[quashlo]

Originally Posted by Cirrus

A couple of more things, just for the record:[list][*]11,000 pphpd is exactly the medium-high capacity range I identified as appropriate for monorail in my last post. Most American at-grade LRT systems that cross streets have less then 5,000, while fully-separated LRT can go up to 20-25,000 (but rarely does). Most third rail metros around the world are in the 30-40,000 range, with a few up to 80,000. 11,000 pphpd is exactly the range where you'd be justified going to the expense of full grade separation, but not enough to need a particularly heavy system. In other words, your numbers show that those two lines fit exactly inside the niche of capacity needs that are appropriate to be served by monorail.

So what happened to your claim that monorail couldn't do the same capacity as elevated light rail? Did it just evaporate?

[twoNeurons]

Can't we all just relax?

There is likely a tipping point when it comes to cost of monorail vs. LRT.

You'd have to be daft to say that from a materials perspective monorails are more expensive. Considering much has been made of how expensive it is to elevate construction, one needs to keep in mind that monorail simply uses far less material and will save on the material costs. For a city like Seattle, which is built on hills, and has most of its LRT grade separated, one could probably have made a case for making it a monorail. What is the tipping point when it comes to grade separation? Is 80% grade separation necessary before monorails are feasible? I don't know.

As for the "AT Grade" portion of Light Rail, there are some places where Vancouver's SkyTrain runs at grade, however, they're completely fenced off. It is of note, however, that the SkyTrain (first two lines) can climb steep grades due to it using a Linear Induction Motor (Magnetic propulsion). It's a hybrid of LRT / heavy rail, mind you.

Being from Vancouver, I can tell you one thing, full automation is a HUGE DEAL. When you have an area with less than 2 million people have a transit system that is able to CHOOSE to run shorter trains at 90 second headways with little extra cost than longer trains, you get a LOT of people taking transit. It also means you can have much shorter stations. STATIONS are a huge capital cost when building lines. The SINGLE question that you need to ask yourself when it comes to LRT vs. monorail is: CAN WE AUTOMATE IT? The medium-term and long-term savings and service benefits are huge. Anyone who has ridden on Vancouver's system knows this. If monorail ends up being cheaper for an automated system, then so be it. But it shouldn't be discounted as a toy.

Also, there should be the option of providing alternative escape paths. How many incidents are there, in reality? What about adding airplane slides built into the train? Surely someone can come up with an innovative solution?

[M II A II R II K]

Upside down monorails can also dip down to as low as grade level too I suppose but never in mixed traffic.

[Cirrus]

Originally Posted by quashlo

Compatibility matters when you have an extensive existing urban rail network to speak of. Not the case for many cities in developing countries (e.g., Chongqing). If you want to claim that these new systems are “1% of the time”, go ahead. I don't care.

Where did anyone talk about mode compatibility for networks? I'm talking about the expense of building an elevated segment when there's no reason to have to do that. If a monorail line would be 100% elevated but the light rail equivalent would be 80% elevated and 20% at-grade, then you'd be spending a lot of extra cash to do that 20% of unnecessary elevated. On the same line. Not a different line in the same system. The same line.

Originally Posted by quashlo

Do you have any comment on my rebuttal regarding pphpd for Chongqing and Tōkyō?

I edited them in before you posted, but probably after you started typing. 11,000 pphpd is exactly the sort of medium-high capacity range I identified as appropriate for monorail, is also in the range of elevated light rail, and is well short of true high capacity metro systems.

Originally Posted by quaslo

Please show me an example of these crossings along elevated light rail stations you seem to think are so common… You will find they are a rarity more than anything, even less than the “1% of situations” you love throwing around with regard to monorail’s applicability.

I didn't say they were common or not a rarity. Elevated light rail itself is a rarity, partly because it's so often unnecessary. But if you're going to dismiss emergency access as irrelevant because it's an operational choice of the US rather than an inherent trait of the mode (which I think is fair), then you have to apply the same standard to light rail crossings. Agencies might choose not to use them, but they are inherently possible. Pedestrian crossings of course limit maximum capacity, but that only starts to come in to play at the upper levels of the capacity equation.

As for the Charlotte example, I've described why it's pertinent multiple times. If you choose to ignore it that's your business. But I promise you that planners making mode decisions on billion dollar investments don't ignore those sorts of design/cost considerations. They are how the choice of modes is made.

Also, in regards to "1% of situations," that's shorthand and you know it. I have provided an extensive post explaining what that actually means. If you'd prefer I just copypaste that post from now on instead of using shorthand, then OK. I will stop saying 1% and will start referring back to that post.

Originally Posted by quashlo

So what happened to your claim that monorail couldn't do the same capacity as elevated light rail? Did it just evaporate?

I didn't make that claim. I claimed that monorail couldn't do the same maximum capacity as elevated light rail (20-25,000 pphpd) without adding to the bulk/weight (therefore the cost and visibility) of the system. I said that the higher your capacity needs go, the less monorail's smaller footprint advantages apply, and the more it looks like regular elevated light rail.

[Cirrus]

Originally Posted by M II A II R II K

Upside down monorails can also dip down to as low as grade level too I suppose but never in mixed traffic.

This is true, but it's very expensive. You're building the entire apparatus for an elevated line even if it is level with the ground. Also, upside down monorails are bulkier and therefore have less of a "low visibility" advantage.

[electricron]

Originally Posted by Cirrus

1)Honolulu's pre-EIS Alternatives Analysis *did* include monorail. I'm not sure why it wasn't advanced, but it was definitely there in the early study stages.[/list]

According to the EIS, there were two main reasons...
(1)System capacity per hour and (2) Standardization.
They needed a higher capacity per hour than smaller monorail vehicles can deliver. They wanted the ability to build and buy standard guideways that many vendors could build standard trains for. Just about in every case with monorail, vehicles are built exclusive to the guideways. For example, the monorail vehicles in Seattle can't be used in Disneyland or Las Vegas - or vice versa.

[quashlo]

Originally Posted by Cirrus

Where did anyone talk about mode compatibility for networks? I'm talking about the expense of building an elevated segment when there's no reason to have to do that. If a monorail line would be 100% elevated but the light rail equivalent would be 80% elevated and 20% at-grade, then you'd be spending a lot of extra cash to do that 20% of unnecessary elevated. On the same line. Not a different line in the same system. The same line.

Sorry, let me elaborate. My point is that monorail has very strong potential (I would argue not simply “niche”) in developing countries because they won’t be able to do street-running anyways. Their streets are too narrow and mixed running presents too much potential for conflict with car and ped traffic. An underground line would solve these problems, but can be prohibitively expensive. The only other alternative is elevated, in which monorail can be an extremely attractive choice from a cost and shadows perspective if you don’t need to worry about compatibility with any existing rail lines. This is the case in many cities in developing countries, which do not have much existing rail infrastructure to speak of. Cities in North America and Europe may not be so constrained for land or may have extensive existing steel-wheel rail networks, so monorail obviously has less to offer in these places.

Originally Posted by Cirrus

As for the Charlotte example, I've described why it's pertinent multiple times. If you choose to ignore it that's your business. But I promise you that planners making mode decisions on billion dollar investments don't ignore those sorts of design/cost considerations.

My understanding is that you claimed that elevated light rail (on aerial structure) technically allows for crossing at track level. You are correct, now show me some examples. Otherwise your point about “cost savings” is moot. What you are describing is certainly not a widely-accepted practice… If a station is elevated on aerials, the circulation will invariably occur underneath the tracks, regardless of whether the mode is monorail, steel-wheeled rail, or rubber-tired guideway.

Of course, if I have misunderstood you, feel free to correct me.

Originally Posted by Cirrus

I didn't make that claim. I claimed that monorail couldn't do the same capacity as elevated light rail (20-25,000 pphpd) without adding to the bulk/weight (therefore the cost and visibility) of the system. I said that the higher your capacity needs go, the less monorail's smaller footprint advantages apply.

I know what you claimed. And I showed you an existing monorail system (Chongqing) that could easily do over 20,000 pphpd if it wanted to, and no, the aerial structure doesn’t have anywhere close to the “bulk” of an elevated light rail aerial structure with the same capacity. It still maintains the same qualities as other (smaller) monorail systems. I don’t see how Chongqing going to 20,000 pphpd requires larger bulk that it approaches what's required for elevated light rail.

And a larger station footprint for monorails is a bit of a fallacy as well… I think those pictures of the Honolulu example show that quite effectively. If you are comparing to at-grade LRT, of course monorail will have a larger footprint, but not if you are comparing to elevated LRT.

[Cirrus]

Originally Posted by quashlo

My point is that monorail has very strong potential (I would argue not simply “niche”) in developing countries because they won’t be able to do street-running anyways... Cities in North America and Europe may not be so constrained for land or may have extensive existing steel-wheel rail networks, so monorail obviously has less to offer in these places.

Fair enough. Although I would hesitate to say that the lack of space for street-running (or off-street at-grade) is anywhere close to universal even in developing countries, and that even in locations where it is the case in the central city it may not be in the outer or newly-developing areas, and therefore will still not apply to lines that leaves the central city. The percentage in developing countries may be higher than 1%, but I would bet it's still a clear minority.

In any event, I don't disagree in principle.

Originally Posted by quashlo

My understanding is that you claimed that elevated light rail (on aerial structure) technically allows for crossing at track level. You are correct, now show me some examples. Otherwise your point about “cost savings” is moot. What you are describing is certainly not a widely-accepted practice… If a station is elevated on aerials, the circulation will invariably occur underneath the tracks, regardless of whether the mode is monorail, steel-wheeled rail, or rubber-tired guideway.

You can do this at any elevated light rail station that doesn't have high platforms, whether it's by design or not. Unless the agency goes to the extra expense to put up a fence, but that's not inherent to the mode. So any elevated station on a system that uses low-floor railcars will qualify. San Diego's Qualcomm and Grantville stations are examples.

Originally Posted by quashlo

I don’t see how Chongqing going to 20,000 pphpd requires larger bulk that it approaches what's required for elevated light rail.

Well there's one way to find out for sure. Find me a monorail with capacity at or above 25,000 and let's see what it looks like. Is there one in the world? If you can, I'll retract that point (but in the mean time I'm going to go add your point about interoperability to my earlier post listing the requirements for a monorail).

[Beta_Magellan]

Originally Posted by Cirrus

[*]Honolulu's pre-EIS Alternatives Analysis *did* include monorail. I'm not sure why it wasn't advanced, but it was definitely there in the early study stages.[/list]

The votes of the technology selection board are outlined in this document, but here are reasons given by members of the board that stick out:

•The most widely used and available transit technology, expected to provide the best competition in procurement

•This system has the best potential for vehicle and system interchangeability for future procurement

•System reliability due to experience and wide range of supplier

•Non-proprietary systems

•Highest level of initial competition [for bids]

•Highest level of future competition [for bids]

•Greatest base of suppliers insuring good competition and long-term support

IIRC, the lack of suppliers was a big issue for the Seattle monorail, which basically only had Hitachi and Bombardier as bidders with non-compatible products (and maybe a Malaysian company—can’t recall).

[quashlo]

Originally Posted by Cirrus

You can do this at any elevated light rail station that doesn't have high platforms, whether it's by design or not. Unless the agency goes to the extra expense to put up a fence, but that's not inherent to the mode. So any elevated station on a system that uses low-floor railcars will qualify. San Diego's Qualcomm and Grantville stations are examples.

I’m talking about high-platform stations. If we are talking about fully-elevated (or even fully grade-separated, for that matter) light rail vs. monorail, you wouldn't design it as low-floor... You'd use high-floor to maximize capacity.

Originally Posted by Cirrus

Well there's one way to find out for sure. Find me a monorail with capacity at or above 25,000 and let's see what it looks like. Is there one in the world? If you can, I'll retract that point (but in the mean time I'm going to go add your point about interoperability to my earlier post listing the requirements for a monorail).

Wait, I gave you one that has a capacity as constructed of higher than that. If we assume that headways are decreased from 3m30s to 2m30s (not a big deal at all) and they began coupling trains:

158 pax / car × 8 cars per train × 24 tph = 30,336 pphpd

What more do you want? It’s not as if they need to reinforce the aerial structures to run coupled trains… It was built to handle eight cars to begin with. The columns are slightly thicker and the beams slightly taller than for a substantially smaller monorail system like the Okinawa example, but the aerial structure still doesn't approach the bulk of steel-wheel rail.