MTA shows latest plans for Silver Spring

MTA held a Silver Spring Station area meeting this evening at the Silver Spring Civic Center, and showed several concept drawings of the most recent design plans for the Purple Line and CCT at the Silver Spring transit station. A snapshot of one of the drawings has just been posted by Chris Gillis, of Councilmember George Leventhal’s staff, as a PLN twitter pic. As Chris indicated in the twitter comment, there is a lot going on there, but it looks like it will all work.

(5/31/2012 update: The MTA has posted its drawings and presentation at www.purplelinemd.com.)

The major change from past MTA renderings is that the Purple Line and the Trail are both higher than previously shown. MTA has raised the proposed Purple Line platform and tracks to be at a fourth level. The CCT would be on an areal structure passing through the station at the third level, while the MARC and Metro Red Line platforms would remain on the second level as they are now. Having the Purple Line at a higher elevation makes it possible to use vertical separation to manage potential conflicts between the trail users and the pedestrian traffic to the MARC and Purple Line platforms. The new arrangement puts the trail on a different level than the train platforms.

The trail would will hold straight and to a 12+ foot width through the station, but there would be a sharp turn at the south end of the station where the CCT would meet the MetBranch Trail. MTA and M-NCPPC planners are aware this is a problem and are trying to work out a more gradual curve alignment, but space is very constrained in that area as the MetBranch Trail and the new “Ripifant” Street Road must both pass under the Purple Line tracks there where the tracks turn to the east.

I will post more on this design in a few days, after the MTA has posted better images of their concept drawings on their website.

7 Responses to “MTA shows latest plans for Silver Spring”

  1. Dan says:

    The maps are now at: http://www.purplelinemd.com/en/public-involvement/neighborhood-work-groups/100-silver-spring-transit-center

    The part that confuses me about this is CCT access. The CCT is going through downtown silver spring 30+ feet above ground level. What’s the trail’s slope going to be to get it to this height from both sides of the station? Will there be any way besides escalators/stairs/elevators to get between the CCT and street level near the station?

  2. admin says:

    @Dan: “Will there be any way besides escalators/stairs/elevators to get between the CCT and street level near the station?”

    The trail is elevated through the entire station area. It will match the existing grade at Apple Street, one block north of Colesville Road, and again at the south end of the station at the new “Ripifont” Street. So the trail will be easy to get onto from the north or south at these points.

    But if you want to go to or from the trail to points in the transit center at the Plaza or second level, then you will have to take elevators or stairs that will be accessible in the general area near where the MARC platforms are now. There will also be a pedestrian ramp going down to the Metro plaza from the south end where the MetBranch and CCT meet.

    waynep

  3. dan reed! says:

    I have to admit I’m a little nervous about the Purple Line being elevated here. According to the engineering drawings, it looks like the platform will be 30 feet above the Red Line and higher even than the top of the Transit Center. The Red Line/CSX tracks already serve as a physical and visual barrier between downtown Silver Spring and the Blairs/South Silver Spring, and I wouldn’t want that to become any worse.

    I’m not an engineer, so I’m willing to give the MTA the benefit of the doubt if they say it needs to be so high up. But I hope that the state is willing to make this new structure and, really, all of the Transit Center, as visually attractive as possible.

    On another note, I was told that the new street will just be named Ripley Street, but that was two years ago. I hope “Ripifant” doesn’t become a reality. There are so many better names for a new street.

  4. admin says:

    @dan:

    I think MTA is boxed into having the Purple Line be high by elevation requirements at both ends of the station. At the north end, the Purple Line bridge that will bring the Purple Line from the west to the east side of the CSX tracks has a strict requirement of how much it must clear the CSX tracks (24′ clear, I believe). At the south end, the Purple Line must be high enough so its structure clears “Ripifant” Road by a good margin (16′ would be a typical street clearance requirement). Add to that the requirement that the Purple Line platform in the center of the station must be level, and there is little room for MTA to lower the track elevation between the needed high elevations at both the north and south ends.

    I agree it will be a challenge to make this high structure not appear to be overbearing. But the south side of the CSX/Metro tracks is lined with high office buildings that will still be much higher than any transit station or Purple Line structures.

    waynep

  5. What about routing the CCT in a separated lane along 2nd Avenue? The road is wide enough and doesn’t have huge car traffic volumes. The Purple Line could be dropped down to the third level. It would still be as intrusive as a freeway overpass, but every little bit helps.

    The national double-stack standard is 22′6″ — does that force the Purple Line up to the fourth level?

  6. admin says:

    @Laurence:

    I doubt that taking the trail out of the stack will help the Purple Line much. Remember that the Purple Line must be at about the fourth level to clear the CSX tracks where it crosses over at the north side of Colesville Road. Railroad clearance standards are greater than are highway clearance standards. There may not be enough distance between that railroad crossover and the transit station platform for the Purple Line to drop down to the third level. (The Purple Line can’t cross over any further north and still clear through the pinch point at the Metro Plaza building.)

    If lowering the trail would help, it would be better to lower the trail to the second level as it was portrayed in earlier plans than to push it out of the transit center. There would likely be conflicts with pedestrian traffic crossing to the MARC platforms at the second level, but that would be less damaging to the integrity of the trail than having the trail cross Colesville Road at-grade and use streets like Wayne and Ramsey, with more at-grade street crossings, to connect to the MetBranch Trail.

    Waynep

  7. I got it, thanks for the explanation. The “stack” is still a complicated and costly 3D puzzle, though. Is there any precedent for it — is there any similar facility elsewhere in the world?

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