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Old 02-12-2015, 12:13 PM
 
Location: Vallejo
14,056 posts, read 16,063,174 times
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Quote:
Originally Posted by urbanlife78 View Post
Ah, so you are trying to compare apples to oranges. Currently the MAX runs on 15 minutes schedules with 4 trains an hour per line, per direction, and can carry a max of 268 people, which comes to just over 2100 people. To match that number with Portland buses, you would have to run 41 buses per hour, per line, per direction to match what four light rail trains can do per hour in Portland.

Now how much does it cost to pay 41 drivers compared to 4, and how much does it cost to fuel 41 buses compared to providing electricity for rail?
A single articulated bus carries about 120. So you'd need about 20 buses. Of course, your math is completely off. 4*268 is not 2,100. It's 1072. So that's 10 buses. That or the trains carry more people.

Breaking down the economics of bus vs MAX - Portland Transport
Max costs $269/hr to operate.
Bus costs $98/hr to operate (higher for articulated buses)

The advantage of the bus is that it scales better. At peak hours If the peak demand is 1072, off peak is maybe 300. Are you going to run trains every 30 minutes? Probably not. Now you need three buses to meet the demand rather than 10. Maybe you do the same thing and continue to run buses every 15 minutes and trains every 15 minutes to provide the same level of service. Advantage bus. The other advantage of the bus is it costs a lot less up front. That's the kind of stuff I find interesting. Hypothetical carrying capacities? /Yawn.
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Old 02-12-2015, 12:20 PM
 
1,478 posts, read 2,000,921 times
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Quote:
Originally Posted by nei View Post
What's the crowd density that actually is?
Read a bit about the system, saw a vid and thought, "That is in no way safe.". So I looked up a report issued by the US fed govt looking at Bogota and they stated that the capacities of their vehicles have been rated at 7 standing people per square meter. The green guide for public sporting events put crowd capacity at 4.7 people per square meter. This is with perfect conditions on standing areas. For reference, the Leppings End at Hillsborough estimated the crowd density gradient on the terraces. Up front (where most died), the density was 8.5 to 10. It was just a mass of crumpled bodies. In certain areas off to the side, it was about 6. In the rest of the pen, it was about 7-8.5 (where some still died). The margin for error for safety isn't there. You get a fire or some smoke and the relative proportion of people getting off one of those buses is extremely low.

Heavy traffic times:

https://www.youtube.com/watch?v=r2ZZUV-nKzI




Quote:
Originally Posted by nei View Post
Except that limit is moot for the US, since few if any US light rail systems reach that limit.
I agree completely, which is why BRT could be used in a wider variety of settings. There are things that are getting tossed aside though. For better or worse, BRT and LRT will often run in dedicated ROW alongside passenger vehicle traffic. Both need to play nicely with one another to get the maximum benefit. BRT and LRT need signal prioritization to function most efficiently. Looking at different capacity requirements for BRT and the impact on intersection disruption when pushing 2K to 5K passengers in a given direction per hour:

2 min headway, 4800 passengers per direction ph, intersection disruption every minute.
3 min headway, 3200, every 90 seconds.
4 min headway, 2400, every 2 minutes.

It's a lot easier for LRT to blend with passenger traffic because we can roughly double the time between intersection disruptions, which will have a cascading effect on traffic circulation everywhere.

Putting either in a highway expressway median eliminates the problem, but then you're restricting potential applications of either due to density patterns around expressways.
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Old 02-12-2015, 12:30 PM
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Location: Long Island / NYC
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Max NYC MTA subway capacity is 3 square feet per passenger or 3.6 people per square meter. The worst cars on the crowded L train are 32% above that at rush hour or 4.7 people per square meter.

http://cityroom.blogs.nytimes.com/20...officials-say/

The article says the peak demand is about 10,000 per hour (between 8 am to 9 am, evening rush hour is more spread out). So 10,000 per hour is a realistic maximum for heavy rail.
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Old 02-12-2015, 12:31 PM
 
Location: Portland, Oregon
46,053 posts, read 29,499,569 times
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Quote:
Originally Posted by Malloric View Post
A single articulated bus carries about 120. So you'd need about 20 buses. Of course, your math is completely off. 4*268 is not 2,100. It's 1072. So that's 10 buses. That or the trains carry more people.

Breaking down the economics of bus vs MAX - Portland Transport
Max costs $269/hr to operate.
Bus costs $98/hr to operate (higher for articulated buses)

The advantage of the bus is that it scales better. At peak hours If the peak demand is 1072, off peak is maybe 300. Are you going to run trains every 30 minutes? Probably not. Now you need three buses to meet the demand rather than 10. Maybe you do the same thing and continue to run buses every 15 minutes and trains every 15 minutes to provide the same level of service. Advantage bus. The other advantage of the bus is it costs a lot less up front. That's the kind of stuff I find interesting. Hypothetical carrying capacities? /Yawn.
268 is per car, Portland runs two per train, so you want to times that by two. Even if Portland were to run single articulated buses rather than their regular buses, the amount of buses that would need to be run would still be 20, which would still put the cost higher to operate for buses to do the same capacity that light rail does.
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Old 02-12-2015, 12:38 PM
 
1,478 posts, read 2,000,921 times
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Quote:
Originally Posted by nei View Post
Max NYC MTA subway capacity is 3 square feet per passenger or 3.6 people per square meter. The worst cars on the crowded L train are 32% above that at rush hour or 4.7 people per square meter.

http://cityroom.blogs.nytimes.com/20...officials-say/
Well that certainly puts things in context, doesn't it? NYC subway cars, at their worst, are still safe with respect to what the UK views as max standing capacity.
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Old 02-12-2015, 01:21 PM
 
2,388 posts, read 2,952,939 times
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Quote:
Originally Posted by Malloric View Post
"PEAK OF THE PEAK" TRENDING TOWARD RECORD

Even more interesting is the “peak of the peak” – numbers obtained from internal modeling, showing riders traveling to the most congested stops in the San Francisco Financial District. Those numbers are trending even higher than the record seen in 2008 – about 49,000 every morning, compared with about 46,000 in 2008.

“Those peak hour trains are the most crowded,” Bolcik said. “We still have capacity, but we are running the maximum number of trains and cars at those times.”


Train strain: BART working on capacity issues as ridership rises to record levels | bart.gov

If you're delivering over 49,000 people in the peak hour to 3 stations, and have other riders who are passing through those stations then it's higher than 21,000. Moreover, the constraints aren't from the capacity of the system or even from demand, the constraints are a budget issue - buying enough rail cars to be able to run 10 car trains every two minutes.


Quote:
As I've long held, I don't have an particular interest in arguing facts with anyone. You don't believe federal government statistics, and that's fine.
No one from the FTA was in Bogota doing passenger counts or poring over their fare card data.

Quote:
Feel free to present stats that you feel are more accurate and we can have a debate on that. I won't, however, accept your opinion on reputable statistics simply because they upset you for not conforming to your bias.
It's not about stats or my bias. I don't have a problem with buses. My problem is with disingenuous arguments. You clearly have a problem with rail to the point of making specious arguments.

You're comparing ridership on an entire trunk and feeder system in large, high density cities in developing countries to single LRT lines in low-density, North American metros of 2 or 3 million. That's the only fact of any import here. I'm not going to point to SEPTA's Regional Rail and try to tell you that it carries 24,000 pph because 13 lines share 5 stations on a 4-6 track trunk line.

Quote:
I also really don't have much interest in esoteric arguments about hypothetical capacities.
So then why are you making one? You could compare different BRT or Busway lines in a dozen or so US cities to LRT in other US or Canadian cities - sometimes even in the same cities. But you're not because you know it doesn't work so instead you're muddling concepts and making transnational comparisons as if you could just pick up TransMilenio and drop it in Denver and, boom, 41,000 pphpd. That is hypothetical.

Last edited by drive carephilly; 02-12-2015 at 01:29 PM..
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Old 02-12-2015, 01:21 PM
 
Location: Vallejo
14,056 posts, read 16,063,174 times
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Quote:
Originally Posted by urbanlife78 View Post
268 is per car, Portland runs two per train, so you want to times that by two. Even if Portland were to run single articulated buses rather than their regular buses, the amount of buses that would need to be run would still be 20, which would still put the cost higher to operate for buses to do the same capacity that light rail does.
Thanks for correcting your math.

Off-peak you could run 5 buses per hour and that would cost a lot less than four trains. You'd have to cut the train frequency to once every 30 minutes (or less) to be cost effective versus the bus. Of course, with wait times that long that might mean one train per hour to make sense. Even in Portland, Pintland time only gets you so far.
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Old 02-12-2015, 01:35 PM
nei nei won $500 in our forum's Most Engaging Poster Contest - Thirteenth Edition (Jan-Feb 2015). 

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Location: Long Island / NYC
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Portland s light rail isn't exactly high volume. CalgRy would be a better example
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Old 02-12-2015, 01:36 PM
 
Location: Vallejo
14,056 posts, read 16,063,174 times
Reputation: 12630
Quote:
Originally Posted by drive carephilly View Post
"PEAK OF THE PEAK" TRENDING TOWARD RECORD

Even more interesting is the “peak of the peak” – numbers obtained from internal modeling, showing riders traveling to the most congested stops in the San Francisco Financial District. Those numbers are trending even higher than the record seen in 2008 – about 49,000 every morning, compared with about 46,000 in 2008.

“Those peak hour trains are the most crowded,” Bolcik said. “We still have capacity, but we are running the maximum number of trains and cars at those times.”
Math fail. Those are busy stations, with about 120,000/day getting on and off cumulatively. If one person gets off at Embarcadero and another gets on, two people passed through the station. Only one was carried at a time.

Quote:
If you're delivering over 49,000 people in the peak hour to 3 stations, and have other riders who are passing through those stations then it's higher than 21,000. Moreover, the constraints aren't from the capacity of the system or even from demand, the constraints are a budget issue - buying enough rail cars to be able to run 10 car trains every two minutes.
Constraint is the stations. System is running at basically capacity. There's some room to improve with better signaling, skip stop service, and redesigned cars with fewer seats since standees take less room. That really only gets you so far when you run into a wall in the number of people that can get on/off in the FiDi.
http://www.bart.gov/sites/default/fi...s/capacity.pdf

Last edited by Malloric; 02-12-2015 at 01:46 PM..
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Old 02-12-2015, 01:43 PM
 
Location: Vallejo
14,056 posts, read 16,063,174 times
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Quote:
Originally Posted by nei View Post
Portland s light rail isn't exactly high volume. CalgRy would be a better example
It's the fifth-most used system in the country. Given, it's got 4 lines. Obviously lesser used systems like Houston or Phoenix are busier than at least some of Portland's lines. Still, it is high volume for the US.
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