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I am more and more curious on light rail technologies and placements.
To tht end a few questions maybe some folks can clarify:
1 - Is elevated Light rail less costly than elevated heavy rail?
2 - Is submerged Light rail less costly than submerged heavy rail?
3- What are the pros and cons of having light rail rail on the street versus potentially running midblocks?
curious on light rail technologies and placements.
Is Light (anything) less costly (or otherwise) than heavy (anything)?
Is submerged Light (anything) less costly (or otherwise) than submerged heavy (anything)?
What are the pros and cons of having light rail rail on the (existing) street
(where most/all users are or are going to/from) versus potentially running mid block
Many and varied; it depends on specifics
I am more and more curious on light rail technologies and placements.
To tht end a few questions maybe some folks can clarify:
1 - Is elevated Light rail less costly than elevated heavy rail?
2 - Is submerged Light rail less costly than submerged heavy rail?
3- What are the pros and cons of having light rail rail on the street versus potentially running midblocks?
No expert but I think you are confusing light rail with rapid transit or commuter rail(both of which are forms of heavy rail).
Light rail is basically the modern day street car.
1. It would cost about the same.
2. Probably about the same
3. Not sure what you mean here
Light rail is cheaper than heavy rail because it does not require it’s own right of way along the whole system. It may have varring degrees of separation but is generally built to run on the street with other traffic.
Chicago for instance has no light rail system. We have the El(rapid transit) and Metra(commuter rail)
The EL has its own right of way. It may be elevated, in a the median of an express way, in the subway, or on the surface of the street in an alley, but it has it’s own right of way. Creating this right of way can be expensive which is why many towns prefer light rail. Having it’s own right of way allows for faster speed and less interference from other traffic.
I am more and more curious on light rail technologies and placements.
To tht end a few questions maybe some folks can clarify:
1 - Is elevated Light rail less costly than elevated heavy rail?
2 - Is submerged Light rail less costly than submerged heavy rail?
3- What are the pros and cons of having light rail rail on the street versus potentially running midblocks?
my understanding is that ROW and electricty supply aside, LR isnt really different in physical infrastructure (tracks and signals mostly) than heavy rail - and Im not sure that overhead power is necessarily much cheaper than 3rd rail power. IIUC the only real advantage to "light" rail (IE rail with overhead power and shorter trains) versus heavy in an elevated or subway scenario, is the ability of running seamlessly with at grade lines - either in streets, or off street but with occasional crossings. The Green line in Boston, for ex, can run from street car mode to underground mode seamlessly. I think in europe they call that "pre metro", since the underground parts can be converted to heavy rail at modest cost.
Street vs midblock - well midblock you need to acquire the right of way, which in built out areas can be very difficult and costly. On street in a dedicated lane you need to pull street area from motor vehicles, which can elicit resistance in a congested area (and its usually congested areas where rail is proposed) Here in Nova, folks have suggested a LR line down Rte 1 towards Ft Belvoir, and folks are already saying "Im not giving up a lane for cars on Rte 1". On street in non dedicated, you dont really get a time advantage - your street cars are stuck in traffic.
The other advantage of being in the streets is presumably a shorter walk from the stop to commercial areas.
my understanding is that ROW and electricty supply aside, LR isnt really different in physical infrastructure (tracks and signals mostly) than heavy rail - and Im not sure that overhead power is necessarily much cheaper than 3rd rail power. IIUC the only real advantage to "light" rail (IE rail with overhead power and shorter trains) versus heavy in an elevated or subway scenario, is the ability of running seamlessly with at grade lines - either in streets, or off street but with occasional crossings. The Green line in Boston, for ex, can run from street car mode to underground mode seamlessly. I think in europe they call that "pre metro", since the underground parts can be converted to heavy rail at modest cost.
Street vs midblock - well midblock you need to acquire the right of way, which in built out areas can be very difficult and costly. On street in a dedicated lane you need to pull street area from motor vehicles, which can elicit resistance in a congested area (and its usually congested areas where rail is proposed) Here in Nova, folks have suggested a LR line down Rte 1 towards Ft Belvoir, and folks are already saying "Im not giving up a lane for cars on Rte 1". On street in non dedicated, you dont really get a time advantage - your street cars are stuck in traffic.
The other advantage of being in the streets is presumably a shorter walk from the stop to commercial areas.
Understood, think i am more thinking to build in lesser developed areas. And the mid block question is to provide ROW with more limited street intersection while still moving at grade. Also the stops would be at the streets so-to-speak. So midblock could run behind street facing commercial lets say on either side, crossing streets midblock with dedicated ROW away from the streets but with stops at the portions where the lines meet a street.
And I guess on the costs, if Light rail is not more cost effecient then why not just build heavy rail (though the use of streets here in developed areas makes the cost likely less as no (or less) additional land is required to be re-aquired for usage.
And to the above agree on the Green Line - in some ways today this line acts as both and accomplishes high passenger volumes/ridership. Philly also has trolley lines that both run above and below ground (in core) but smaller (shorter in length) and less speedy when compared to the green. They call these the subway surface lines in Philly.
“And I guess on the costs, if Light rail is not more cost effecient then why not just build heavy rail (though the use of streets here in developed areas makes the cost likely less as no (or less) additional land is required to be re-aquired for usage.”
Light rail saves costs because it does not have a dedicated right of way along the whole route.
Building bridges (to elevate) or builing subways is expensive. The shorter and narrower cars gives a light rail car the ability to take sharper turns than a heavy rail and use less space.
Basically if it needs to run on the street for much of the route light rail is(or can be) a better option.
The difference between light rail and heavy rail is in that video. Notice how the street car moves with traffic. In a heavy rail situation like the EL, crossing gates would come down and everyone would stop to allow the el to cross the street. Plus the el never runs on the street itself (if it is at grade level it is tucked into an alley) and does not stop on the street (it stops at stations always).
I wonder if they could make a street running light rail run faster by having the traffic signals turn green when the train comes close?
I think some systems have that feature. The thing about light rail is that is can have some heavy rail features like subways but unlike heavy rail the whole route does not need to be totally seperated from all other traffic.
And I guess on the costs, if Light rail is not more cost effecient then why not just build heavy rail
uh yeah. well.
LRT works very well where A. running in the streets works (see Boston) B. You have some nice property where you can easily put in LRT but where heavy rail (which would mean no at grade crossings or even short operations in the street) would be difficult (see baltimore) C. some combination (san diego, several other places)
But to some degree LRT just has cachet that "dirty smelly subways" dont have.
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