Quote:
Originally Posted by sphansen
You build heavy rail because of speed and capacity needs. If Light Rail isn't capping out either of those needs, you don't need heavy rail.
|
Light rail vs heavy rail isn't an on-off switch between bare-bones versus subway. It's a whole spectrum. You can have light rail lines like Seattle or Honolulu with many of the features of heavy rail, and you can have heavy rail systems like Cleveland's Red Line that really work more like light rail.
Even within SLC you see differences. The S-Line only has a single track, while the others are double-tracked. Do you think the S-Line being single-tracked proves that every double-tracked light rail line in SLC is over-built? Obviously it's possible to build light rail like the S-Line, so why bother going to the trouble of 2 tracks? Or longer trains?
Even subways have spectrums. BART is built to handle trains up to 10 cars long. DC's Metro is built for 8. Both of them are 100% double-tracked, which sounds nice until you see the 4-track lines in New York, Chicago, and Philadelphia capable of running express trains that skip most of the stations.
It's all a spectrum. You design to your needs.
Quote:
Originally Posted by s.p.hansen
Why does the station I posted a pic of have two sets of escalators on each side of the platform?
|
Probably because escalators inevitably break down & have to be rebuilt, and that station is so high up that making people walk on stairs (ie broken escalators) would seriously (and dangerously) slow down circulation. So they add a redundant set, to make sure there can always be working escalators in both directions.
Here's a more extreme example from DC: Imagine if this station had been built with only one escalator, and it broke down. Would you want to huff it up those steps?
Dee on flickr
And before you mention that station has only 3 escalators: We've been finding in DC that the stations don't have enough access points, and have been adding new mezzanines, escalators, and elevator banks to several stations like this one in recent years, at great expense. It would have been cheaper if we'd built them with enough vertical circulation capacity originally.