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Old 02-10-2013, 06:06 PM
 
Location: Vallejo
14,061 posts, read 16,074,613 times
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Quote:
Originally Posted by nei View Post
check the link I posted on the previous page. Rail does much better in CO_2 emissions per person. Since rail usually gets its energy source from electricity the fuel consumed to make the same amount of energy is less.
A gallon of fuel has a set amount of energy. Whether you burn it for heat, burn it in an ICE for either mechanical propulsion or to generate electricity, or just leave it sitting there it has the same exact amount of energy. I get what you're trying to say, that generating electricity is often more efficient, but you're completely wrong in how you're going about it. A combined cycle gas turbine operates in the 50-60% efficiency range, that is they can capture about 50-60% of the energy in a gallon of gasoline and turn it into electricity, then add the transmission loss and loss of the electric motors. The ICE in a car or bus is more in the 20% range. In either case, you aren't making energy. That's impossible.

The reason transit from electricity has better CO2 emissions often depends on the source of the electricity. BART does very well because California's energy is more than 1/3 renewable, hydro and nuclear (which release very little CO2), 50% natural gas (which releases less than gasoline), and only a small amount of coal. The efficiency helps as well, but the pumping losses are included in BTU per mile or CO2 per mile. Cars don't get a 80% reduction in BTU/mile simply because they only use 20% while the other 80% is wasted as heat.

Last edited by Malloric; 02-10-2013 at 06:19 PM..
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Old 02-11-2013, 12:06 AM
 
2,941 posts, read 3,858,066 times
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Quote:
Originally Posted by texdav View Post
There is alot more to it than just fuel cost. City of 120K nearby is studdig what to do when federal subsidy goes awya. 1.3 millio a year to ru the system. 300K in fairs. The rest is split between city and federal grant moneies. They have found that they coulod c=subsidie and pay atxi for less cost and more convenience to users really.
From what I have read no federal subidy for public transit since the 80ies. There are some federal money like for building new rail lines, aquiring equipment, repair rail lines but none for running the agency itself(i.e. Paying drivers ect..) and 1.3 milllion ain't going to buy enough taxies for that many people depending on how far they need to travel esp. not if they travel in ones and two like most taxi users. There may be subsidies for things like green fuel useage and for some transit subsides but that is about it.

In short you can get federal money for many things but not for running the system itself.
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Old 02-11-2013, 12:42 AM
 
Location: Vallejo
14,061 posts, read 16,074,613 times
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Quote:
Originally Posted by chirack View Post
From what I have read no federal subidy for public transit since the 80ies. There are some federal money like for building new rail lines, aquiring equipment, repair rail lines but none for running the agency itself(i.e. Paying drivers ect..) and 1.3 milllion ain't going to buy enough taxies for that many people depending on how far they need to travel esp. not if they travel in ones and two like most taxi users. There may be subsidies for things like green fuel useage and for some transit subsides but that is about it.

In short you can get federal money for many things but not for running the system itself.
You've read some stuff that's completely wrong. Sacramento's transit agency got $25.6 million in federal operating funds.
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Old 02-11-2013, 08:39 AM
 
10,630 posts, read 23,412,818 times
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I have NEVER seen anyone on these boards advocate for all bus routes running every 10 minutes. I think all of us realize that that would be wasteful.

But... it does become a chicken-and-egg situation that when buses run infrequently, fewer people want to ride them. Increase frequency and more people want to ride them. Of course you need to have a high enough density of people to give you some reason to think that if you have buses running, say, every 15 minutes, that you'll get enough people on them to justify the costs. You can't do that in a lower-density area, and I don't think most people would consider it a worthwhile expense.

From what I vaguely recall from my transit readings, I think around 7 or 8 units per acre can generally support minimal transit with buses every half hour, while you need closer to 30 units per acre to support high-frequency (10 minute) bus service. I'm not sure if those numbers are accurate, and I realize there are many other factors, but 7 or 8 units per acre is pretty low-density, while on the opposite end it's pretty easy for urban neighborhoods to hit 30 units per acre.
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Old 02-11-2013, 10:08 AM
 
Location: IL
2,992 posts, read 4,418,425 times
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Quote:
Originally Posted by memph View Post
I still wonder what the efficiency of buses in larger cities is though. And while you could increase fuel efficiency by using smaller buses on low ridership routes, people could also use more fuel efficient cars...
Do we have cities that use smaller busses, almost like vans instead of buses? Thsi si a real question, I don't know the answer. I know when I go down to Brazil they have bus routes that use vans, but I believe these are private companies. Anyway, the question is, do we actually use smaller buses in our cities anywhere? Maybe a van that can hold 10 people?
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Old 02-11-2013, 10:25 AM
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
45,987 posts, read 41,947,535 times
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Quote:
Originally Posted by almost3am View Post
Do we have cities that use smaller busses, almost like vans instead of buses? Thsi si a real question, I don't know the answer. I know when I go down to Brazil they have bus routes that use vans, but I believe these are private companies. Anyway, the question is, do we actually use smaller buses in our cities anywhere? Maybe a van that can hold 10 people?
My transit agency uses van-size buses for a couple of routes, mostly afternoon. The issue is that at peak hours a full size bus may fill up and a van size bus isn't going to cut it. It's expensive to keep two sets of vehicles, so a transit agency just keeps full size buses and wastes fuel.
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Old 02-11-2013, 10:31 AM
Status: "Summer!" (set 17 days ago)
 
Location: Foot of the Rockies
86,995 posts, read 102,568,112 times
Reputation: 33059
Quote:
Originally Posted by almost3am View Post
Do we have cities that use smaller busses, almost like vans instead of buses? Thsi si a real question, I don't know the answer. I know when I go down to Brazil they have bus routes that use vans, but I believe these are private companies. Anyway, the question is, do we actually use smaller buses in our cities anywhere? Maybe a van that can hold 10 people?
My transit agency uses them for "Call and Ride", which contrary to the belief of many people on this forum is NOT the same as "paratransit". Much of the time, there is only one person on the bus, at least for part of the route. Anyway, I agree with nei that it's pretty expensive to keep a couple sets of vehicles.

Where were you in Brazil, BTW?
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Old 02-11-2013, 10:47 AM
 
Location: IL
2,992 posts, read 4,418,425 times
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Quote:
Originally Posted by Katiana View Post
My transit agency uses them for "Call and Ride", which contrary to the belief of many people on this forum is NOT the same as "paratransit". Much of the time, there is only one person on the bus, at least for part of the route. Anyway, I agree with nei that it's pretty expensive to keep a couple sets of vehicles.

Where were you in Brazil, BTW?
Rio. I see them running all the time and they appear to have really good ridership.
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Old 02-11-2013, 11:44 AM
 
Location: The Port City is rising.
8,799 posts, read 10,709,555 times
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my goodness, go away and it gets completely off topic.

This thread was NOT intended to be about the costs and benefits of policies to induce more people to take transit.

Each such policy has its own costs and benefits, and needs to be evaluated differently - and likely will or will not make sense based on local conditions.

It was meant to clarify the misleading 'factoid' on higher average fuel burn per passenger compared to autos.

To clarify that the bus average is pulled down by the fact that most bus operations are structured to provide mobility to those who cannot drive, which is a policy goal orthogonal to reducing fuel burn.
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Old 02-11-2013, 11:48 AM
 
Location: The Port City is rising.
8,799 posts, read 10,709,555 times
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Quote:
Originally Posted by Katiana View Post
@Hands, don't hurt yourself! I did like the picture!

Could we all agree that bus systems have some positive attributes even if they aren't more efficient than cars in transporting passengers?
that was exactly the point of my OP. That a subset of bus lines are run to provide basis mobility to people who for whatever reason cannot drive.

If you simply counted them seperately, you would get a different result in terms of bus vs car fuel efficiency.
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