HomeDiagramsDatabaseMapsForum About
     

Go Back   SkyscraperPage Forum > Discussion Forums > Transportation


Reply

 
Thread Tools Display Modes
     
     
  #41  
Old Posted Apr 14, 2012, 5:36 PM
bunt_q's Avatar
bunt_q bunt_q is offline
Provincial Bumpkin
 
Join Date: Aug 2002
Location: Denver, CO
Posts: 13,201
Quote:
Originally Posted by BnaBreaker View Post
That makes a lot of sense! Thank you Electricron for that very precise and detailed answer.
Electricon's answer is right on...except, as he pointed out, when it's not, which is why it's such a tough question to answer.

(1) Light rail trains don't share lanes with other traffic while streetcars will... except that some light rail does operate in shared ROW.

(2) Light rail trains can use multiple units while streetcars don't....typically true, but many streetcar vehicles can be coupled into at least 2-units.

(3) Streetcars can turn tighter curves than light rail trains....can and should are not the same thing. Light rail typical is 82-feet, streetcars you can ratchet down to 50-feet... but then, light rail can theoretically go tighter. And most design specifications you'll see for streetcar systems call for the light rail standard anyways (less wear and tear on the vehicles; higher operating speeds). But this is an important factor in vehicle selection, so it's as good of a criterion to use as any.

So like anything else, the answer is, it depends. The light rail/streetcar distinction is very much an American thing, and as I think Cirrus pointed out, it stems from our habit of using light rail as a "metro light." But that is by no means necessary - plenty of places mix and mingle the two vehicle types operationally.

In the U.S., I think the easiest distinguishing characteristic is shared ROW versus not. That might require us to re-think some of the older light rail systems, but so what?
Reply With Quote
     
     
  #42  
Old Posted Apr 15, 2012, 4:12 AM
bmfarley's Avatar
bmfarley bmfarley is offline
Long-Time Californian
 
Join Date: Nov 2005
Location: California; All Over
Posts: 1,302
Quote:
Originally Posted by Lipani View Post
San Diego is working on an 11-mile mid-coast extension for the trolley to UCSD and UTC, although I'm not sure if any actual construction has started yet since part of that project will be using an existing rail corridor.
But, it is not yet under construction.
__________________
- Think Big, Go Big. Think small, stay small.
- Don't get sucked into a rabbit's hole.
- Freeways build sprawl. Transit builds cities.
Reply With Quote
     
     
  #43  
Old Posted Apr 15, 2012, 2:33 PM
JDRCRASH JDRCRASH is offline
Registered User
 
Join Date: Mar 2007
Location: San Gabriel Valley
Posts: 8,087
bunt_q, what about max speed? Could that be a distinction?
__________________
Revelation 21:4
Reply With Quote
     
     
  #44  
Old Posted Apr 15, 2012, 3:22 PM
electricron's Avatar
electricron electricron is offline
Registered User
 
Join Date: Aug 2008
Location: Granbury, Texas
Posts: 3,523
Lightbulb

Quote:
Originally Posted by JDRCRASH View Post
bunt_q, what about max speed? Could that be a distinction?
Not when the same transit agency is using the exactly same equipment to do both functions. Although generally streetcars are designed to go a max of 45 mph while light rail trains are usually a max of 55 mph. But the real max speed for streetcars in operation is the speed limit of all the other traffic on the same streets. That also usually sets the max speed of street running light rail trains too. This sort of makes the actually max speed of the streetcars/light rail trains equipment irreverent for street running applications.
Reply With Quote
     
     
  #45  
Old Posted Apr 15, 2012, 7:21 PM
SnyderBock's Avatar
SnyderBock SnyderBock is offline
Robotic Construction
 
Join Date: Sep 2006
Posts: 3,833
LRT is also has 65mph variants which are very common.
__________________
Automation Is Still the Future
Reply With Quote
     
     
  #46  
Old Posted Apr 15, 2012, 11:09 PM
electricron's Avatar
electricron electricron is offline
Registered User
 
Join Date: Aug 2008
Location: Granbury, Texas
Posts: 3,523
Lightbulb

Quote:
Originally Posted by SnyderBock View Post
LRT is also has 65mph variants which are very common.
True, but I don't recall ever seeing any light rail trains going 65 mph in city streets. You will see those speeds in tunnels and aerial guideways where they are basically grade separated from other traffic. One could possibly build a streetcar going that fast, but why when their speeds are limited to speeds of the city streets? Could a streetcar ever accelerate to those speed before having to slow down for the next stop 1/8, 1/4, to 1/2 mile away?

We're not defining the differences between the vehicles anymore, but rather defining the difference between overall systems. Which is what I've been suggesting all along.
Reply With Quote
     
     
  #47  
Old Posted Apr 16, 2012, 1:30 AM
TarHeelJ TarHeelJ is offline
Registered User
 
Join Date: Oct 2009
Posts: 1,998
Atlanta's current streetcar project is actually 2.7 miles rather than 1.4 miles. I didn't see where anyone corrected that. http://www.atlantadowntown.com/_file...cember2011.pdf
Reply With Quote
     
     
  #48  
Old Posted Apr 16, 2012, 2:05 AM
ardecila's Avatar
ardecila ardecila is offline
TL;DR
 
Join Date: Jun 2006
Location: the city o'wind
Posts: 16,356
The whole concept of light rail when it was devised back in the 70s was to create hybrid regional systems at a lower cost than full-fledged metro/heavy-rail technology could deliver (BART and MARTA demanded huge sums of money and Baltimore/Miami were cut off before they could build a full system). The result was something that was a mix of streetcar and metro systems. This had precedents in systems like LA's, Philly's, and Newark's, where regular surface streetcars were routed into downtown subways to avoid street congestion.

In the 70s, the situation was reversed - planners realized that many downtowns had extensive downtown street grids that were under capacity, where lanes or entire streets could be given over to surface rail, avoiding the insane cost of downtown subways. In city neighborhoods and suburbs, freight-rail or freeway ROWs could be used to ensure high speeds, which were necessary in order to reach suburban destinations in reasonable amounts of time. These systems would have varying degrees of grade separation depending on the desired train speed and the levels of road traffic at each crossing.

Of course, because light-rail is just a way to describe some form of hybrid, it's impossible to define what IS and is NOT light rail. This is why Houston is building a "light-rail" system that's really just a big streetcar network, and why Honolulu is building a "light-rail" system that's really just a metro with short trains.
__________________
la forme d'une ville change plus vite, hélas! que le coeur d'un mortel...
Reply With Quote
     
     
  #49  
Old Posted Apr 16, 2012, 6:35 PM
mwadswor's Avatar
mwadswor mwadswor is offline
The Man
 
Join Date: Apr 2009
Location: Tempe, AZ
Posts: 1,536
The 3 mile Mesa extension of the Phoenix light rail line is under construction.

Also, I'm not sure if you're counting people mover systems, but the Phoenix Sky Harbor people mover is under construction and on schedule to open late next year.
__________________
Photothreads on Tempe Town Lake, Santa Fe and the Rail Runner, Baltimore, and the Phoenix Sky train.
Reply With Quote
     
     
  #50  
Old Posted Apr 23, 2012, 11:33 PM
seaskyfan seaskyfan is offline
Registered User
 
Join Date: Feb 2006
Location: Seattle
Posts: 3,751
Seattle's First Hill Streetcar line broke ground today.

http://www.seattlestreetcar.org/
Reply With Quote
     
     
  #51  
Old Posted Apr 25, 2012, 5:45 AM
arkhitektor arkhitektor is offline
Registered User
 
Join Date: Feb 2005
Location: Clearfield, UT
Posts: 1,767
FWIW- Construction of Salt Lake's Sugarhouse Streetcar (2.74 miles) is now underway, though the 'official' groundbreaking isn't until next month:

http://www.rideuta.com/mc/?page=Proj...r-Construction
Reply With Quote
     
     
  #52  
Old Posted Apr 30, 2012, 8:06 PM
N830MH N830MH is offline
Registered User
 
Join Date: Jan 2011
Location: Phoenix, AZ
Posts: 2,967
Quote:
Originally Posted by mwadswor View Post
The 3 mile Mesa extension of the Phoenix light rail line is under construction.

Also, I'm not sure if you're counting people mover systems, but the Phoenix Sky Harbor people mover is under construction and on schedule to open late next year.
Yes, please followed the link:

This is only for Central Mesa 3.1 mile extension.

http://www.facebook.com/#!/METROrailConstruction

And also, there is more PHX SkyTrain. You can see how is construction in progress.

http://www.facebook.com/#!/PHXSkyHarbor

You can see how is construction in progress. You will see it.

Last edited by N830MH; May 1, 2012 at 6:23 AM.
Reply With Quote
     
     
  #53  
Old Posted Apr 30, 2012, 8:48 PM
Cirrus's Avatar
Cirrus Cirrus is offline
cities|transit|croissants
 
Join Date: Jul 2001
Location: Washington, DC
Posts: 18,344
Quote:
Originally Posted by TarHeelJ
Atlanta's current streetcar project is actually 2.7 miles rather than 1.4 miles
2.7 track miles, which means including the tracks in both directions. Basically double-counting.

Quote:
Originally Posted by mwadswor
The 3 mile Mesa extension of the Phoenix light rail line is under construction. Also, the Phoenix Sky Harbor people mover is under construction.
The Mesa web site says construction has not started yet. *Design* has started, but not construction. The facebook page N830MH linked to says construction starts on May 30. And no, I'm not going to include airport people movers; some of them might be rail, but we can all agree they're a different animal than urban rail.

Quote:
Originally Posted by seaskykfan
Seattle's First Hill Streetcar line broke ground today.
Quote:
Originally Posted by arkhitektor
Construction of Salt Lake's Sugarhouse Streetcar (2.74 miles) is now underway
Quote:
Originally Posted by Cirrus
San Francisco SMART will go on in 2 weeks.
Added these three to the list.
__________________
writing | twitter | flickr | instagram | ssp photo threads
Reply With Quote
     
     
  #54  
Old Posted May 1, 2012, 2:02 PM
northbay's Avatar
northbay northbay is offline
Sonoma Strong
 
Join Date: Mar 2006
Location: Cotati - The Hub of Sonoma County
Posts: 1,882
Quote:
Originally Posted by Cirrus
San Francisco SMART will go on in 2 weeks.
Quote:
Originally Posted by Cirrus View Post
Added these three to the list.
Thanks! I saw some construction workers the other day. It's finally started!
__________________
"I firmly believe, from what I have seen, that this is the chosen spot of all this Earth as far as Nature is concerned." - Luther Burbank on Sonoma County.

Pictures of Santa Rosa, So. Co.
Reply With Quote
     
     
  #55  
Old Posted May 11, 2012, 9:43 PM
bobg bobg is offline
Registered User
 
Join Date: Jul 2011
Posts: 466
Relatively minor but RTD broke ground on the 1.5 mile I225 LRT extension from 9 mile to Iliff today.

They are still in the RFP process to extend it beyond Iliff. That process was initiated after Kiewit's unsolicited bid to finish the rest of that corridor.

Last edited by bobg; May 11, 2012 at 10:13 PM.
Reply With Quote
     
     
  #56  
Old Posted May 12, 2012, 10:13 PM
SnyderBock's Avatar
SnyderBock SnyderBock is offline
Robotic Construction
 
Join Date: Sep 2006
Posts: 3,833
Quote:
Originally Posted by electricron View Post
Not when the same transit agency is using the exactly same equipment to do both functions. Although generally streetcars are designed to go a max of 45 mph while light rail trains are usually a max of 55 mph. But the real max speed for streetcars in operation is the speed limit of all the other traffic on the same streets. That also usually sets the max speed of street running light rail trains too. This sort of makes the actually max speed of the streetcars/light rail trains equipment irreverent for street running applications.
Quote:
Originally Posted by SnyderBock View Post
LRT is also has 65mph variants which are very common.
Quote:
Originally Posted by electricron View Post
True, but I don't recall ever seeing any light rail trains going 65 mph in city streets. You will see those speeds in tunnels and aerial guideways where they are basically grade separated from other traffic. One could possibly build a streetcar going that fast, but why when their speeds are limited to speeds of the city streets? Could a streetcar ever accelerate to those speed before having to slow down for the next stop 1/8, 1/4, to 1/2 mile away?

We're not defining the differences between the vehicles anymore, but rather defining the difference between overall systems. Which is what I've been suggesting all along.
I wasn't making a case for LRT to be used at 65mph in city streets. I was simply pointing out that they max out at 65mph, not 55mph. Depends on the model, yes, but the splits between Streetcar max speeds and LRT max speeds should be: 45mph max for Streetcars and 65mph max for LRT. That was all, I was saying.
__________________
Automation Is Still the Future
Reply With Quote
     
     
  #57  
Old Posted May 13, 2012, 1:35 AM
djggrind djggrind is offline
Registered User
 
Join Date: Feb 2011
Posts: 3
Salt Lake City Draper extension missing

The Salt Lake City UTA 3.8 mile Draper light rail extension is missing as under construction. http://www.rideuta.com/mc/?page=Proj...e-Construction
Reply With Quote
     
     
  #58  
Old Posted May 13, 2012, 5:06 AM
nomarandlee's Avatar
nomarandlee nomarandlee is offline
My Mind Has Left My Body
 
Join Date: Jan 2006
Posts: 3,334
Quote:
Originally Posted by bnk View Post
There are 4 expansion proposals in this link 3 of them look good. But some fourmers are very passionate for hating the Starline proposal. Fine what ever, the other 3 should progress. When or if they get done?
.
With good reason. Other then looking impressive on agency maps with superficial connectivity it would really provide very little excepting taking people to nowhere places to other nowhere places. It is MUCH to spend billions of dollars elsewhere on Metra lines. The other three projects (particularly the UP-W and UP-NW improvements) are very worthwhile IMO.

By the way a few years ago there was a press release about extending the Milwaukee North Line (Fox Lake) to have a split branch up north by Rockland Rd. that would extend north to Gurnee. Giving its proximity to Gurnee Mills, Six Flags, Lambs Farm, and Abott Laboratories I thought would have been a real good idea. Haven't heard anything about it since however.
Reply With Quote
     
     
  #59  
Old Posted May 15, 2012, 7:12 PM
lawfin lawfin is offline
BANNED
 
Join Date: Sep 2008
Location: Chicago
Posts: 1,697
Quote:
Originally Posted by nomarandlee View Post
With good reason. Other then looking impressive on agency maps with superficial connectivity it would really provide very little excepting taking people to nowhere places to other nowhere places. It is MUCH to spend billions of dollars elsewhere on Metra lines. The other three projects (particularly the UP-W and UP-NW improvements) are very worthwhile IMO.

By the way a few years ago there was a press release about extending the Milwaukee North Line (Fox Lake) to have a split branch up north by Ro....ckland Rd. that would extend north to Gurnee. Giving its proximity to Gurnee Mills, Six Flags, Lambs Farm, and Abott Laboratories I thought would have been a real good idea. Haven't heard anything about it since however.
I for one wish Metra would for once focus on increasing train frequency on its more heavily used lines, even if this runs were "limited runs".....that is runs that didn't proceed to line terminus. I think the north line for instance should run on the half hour during the week; and perhaps eeven on Saturday, every hour or so on Sunday would be sufficient. Quit expanding to area where the stations might get 100 riders a day instead increase frequency in the inner metra region to turn metra into a more viable comprehensive transportation alternative.
Reply With Quote
     
     
  #60  
Old Posted May 15, 2012, 7:46 PM
k1052 k1052 is offline
Registered User
 
Join Date: Oct 2007
Posts: 2,235
Quote:
Originally Posted by lawfin View Post
I for one wish Metra would for once focus on increasing train frequency on its more heavily used lines, even if this runs were "limited runs".....that is runs that didn't proceed to line terminus. I think the north line for instance should run on the half hour during the week; and perhaps eeven on Saturday, every hour or so on Sunday would be sufficient. Quit expanding to area where the stations might get 100 riders a day instead increase frequency in the inner metra region to turn metra into a more viable comprehensive transportation alternative.
Ramping up city service with new infill stations and more frequency would probably require electrification. Not that it isn't a conversation worth having since Metra already blows through populated areas that have less than ideal CTA rail access.

Getting UP to seriously discuss electrification is going to be...challenging. Maybe Metra could do a pilot program on the RI first.
Reply With Quote
     
     
This discussion thread continues

Use the page links to the lower-right to go to the next page for additional posts
 
 
Reply

Go Back   SkyscraperPage Forum > Discussion Forums > Transportation
Forum Jump


Thread Tools
Display Modes

Forum Jump


All times are GMT. The time now is 2:21 PM.

     
SkyscraperPage.com - Archive - Privacy Statement - Top

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.