The Washington, DC region is great >> and it can be greater.


How the Purple Line will fit through the Silver Spring Transit Center

The Purple Line and the Capital Crescent Trail/Metropolitan Branch Trail will both have to fit through the Sarbanes multi-modal transit center, currently under construction. So far, the maps and plans haven't made clear how the Metro line, CSX tracks, trail, and Purple Line can all fit. Based on MTA drawings, they plan to accomplish this by building an elevated Purple Line above the trail through the transit center and over to Bonifant Street.

The Silver Spring Metro Station
Looking north at the Silver Spring Metro Station from the north end of the MARC platform. (Nov. 4, 2009)

The concept plan to bring the future Capital Crescent Trail into the new transit center from the north end is easy to envision. There is room for the trail to be built along the east side of the CSX/Metro tracks and at about the same level as the CSX tracks, to be supported on a new elevated trail structure. The Purple Line will also be coming into the center from the north end and on the same side of the CSX/Metro tracks as the trail, but supported on new structure at a higher level than the trail.

The Purple Line must be much higher as it enters the station from the north, because the Purple Line must cross over the CSX tracks from the west to east side immediately north of Colesville Road. Under CSX rules, the Purple Line structure must clear the CSX tracks by at least 27' at the cross over bridge. Light rail tracks cannot change elevation quickly, so the Purple Line will remain well above the future CCT as it comes into the transit center from the north side of Colesville Road.

The Silver Spring Metro Station
The Purple Line tracks and station platform will be along the east (right) side of the CSX tracks, and higher than the "gull wing" roof over the Red Line Metro platform.

But what about from the south? I had assumed the Purple Line would be gradually dropping elevation as it approached the south end of the transit center, to come much closer to the trail elevation. MTA and County planners had given their assurance that space had been reserved for both the Purple Line and trail, but it wasn't clear how the south end of the MARC platform, the two Purple Line tracks, and the Met Branch Trail could all fit between the CSX tracks and the new transit center bus platforms if they were at about the same level. And there was the problem of how to have the Purple Line cross the Met Branch Trail as the Purple Line made its turn east toward Bonifant Avenue. The MTA transit center renderings to date don't show anything to clarify this.

The Purple Line alignment at the transit station
The Purple Line alignment at the transit station. Source: (See LPA-13 at "Conceptual Plans"; See LPA-12 for alignment over Colesville Road)

The MTA conceptual plan above shows where the Purple Line will turn east at the south end of the transit center. The Met Branch Trail is not shown. It will be along the east side of the CSX corridor as it enters the transit center area from the south.

MTA engineers commented at the MTA Purple Line focus group meeting for downtown Silver Spring on Nov. 2 that it would be tight for them to bring the Purple Line "down" to meet the elevation of Bonifant Street after leaving the transit center and turning east. The Purple Line must meet the existing Bonifant Street elevation east of Ramsey Avenue to continue east on dedicated lanes on the south side of Bonifant Street. But Bonifant Street is much higher than the CSX track elevation, so why is it a tight fit to bring the Purple Line elevation down to Bonifant Street?

The MTA Purple Line elevation drawing in this area (available online at at Maps and Graphics / Conceptual Plans / PDF file LPA-47) shows the tracks staying at a constant high elevation through the transit center and then rising as the Purple Line begins the turn east toward Bonifant Street, to stay well above the ground level. The highest point for the Purple Line tracks is near the middle of the turn. The Purple Line will then stay high, and even climb a little at the south end of the new transit center, to accommodate a new Bonifant Street/Ramsey Avenue road connection called for in the Ripley area development plans.

Aerial view of Ripley development area
"Midtown Silver Spring" site in the Ripley development area. Source: Planning Board Sept. 18, 2008 archived agenda (PDF file at item #5)

The Montgomery County Planning Board has approved site plans for tall residential buildings on both sides of Ripley Street—the "Midtown Silver Spring" project shown above and also a "1050 Ripley" project immediately opposite on the south side of Ripley Street. Site plans for both projects show similar plans for Ripley Street to be extended to connect to Bonifant Street, to improve area street circulation.

Site plan for Ripley project
Plan to extend Ripley Street to Bonifant Street, room is reserved for the Met Branch along the CSX tracks (trail not shown). Source: Planning Board July 3, 2008 archived agenda (PDF file at item #4)

The highest Purple Line elevation shown in the MTA conceptual drawing corresponds to the location over the Ripley Street extension where the extension comes out at the end of Bonifant Street. The Purple Line is more than 20 feet above the existing ground elevation there, to allow the Ripley Street extension to pass under the Purple Line. The Purple Line will begin to descend to meet the grade of Bonifant Street after it has cleared the Ripley Street extension.

Looking toward Bonifant Street
Looking up toward Bonifant Street from the MARC platform. The Ripley Avenue extension and Met Branch Trail will be at grade,
while the Purple Line tracks will be elevated.

In brief, the CCT/Met Branch can stay at the same level as the CSX/Metro tracks through the transit center and beyond. The Purple Line is planned to stay much higher through the transit center and around the first part of its turn east at the south end of the transit center. The Met Branch Trail can easily pass under the Purple Line at the south end of the transit center, for a straight and grade separated crossing. Because the Purple Line stays elevated, the trail can be partially under the Purple Line structure through the entire transit center to make room for more than a full width trail within the space reserved for the project.

This is only a concept plan at this time. It is a long way to final design and construction. But it is reassuring to see the MTA Purple Line plans and the County area development plans are consistent with each other and will support a direct, level CCT/Met Branch Trail alignment with no at grade crossings of either roads or rail.


Add a comment »

So how will the purple line fit into the actual metrostation; will there be separate entrances this could be a great chance to remodel the station.

Perhaps they could have a set of escalators/elevator start on the red line platform and go above the CSX rails and over to the purple lines platform to make it easy to transfer between the two line rather than leaving one and reentering via the current entrance.

by kk on Nov 11, 2009 2:34 pm • linkreport

I'm boycotting that station until they bring back the penguin murals. Otherwise, sounds great.

by Zekeo on Nov 11, 2009 2:43 pm • linkreport


"So how will the purple line fit into the actual metrostation..?"

That is an important question, and your suggestion for a new set of escalators/elevator to allow direct transfer from Red Line platform to Purple Line platform would be a huge benefit. But I haven't seen anything from MTA yet beyond elevators and escalators from the Purple Line platform down to the current entrance. I've heard WAMATA considers remodeling the Red Line station as a huge and unwelcome expense. But this should be looked at seriously.

by Wayne Phyillaier on Nov 11, 2009 2:46 pm • linkreport

The question of how the Purple and Red Line stations will connect will be complicated by what sort of fare regime the Purple Line uses, right? At least some of the Purple Line's stations are going to be relatively simple at grade platforms that can't really be faregate-controlled, which means that you would need separate entrances for the two lines where they connect.

by jfruh on Nov 11, 2009 3:12 pm • linkreport

Hopefully you can pass from one line to the other directly or at least those with SmartPasses can go from one to the other through faregates.

The technology exists for transferring between different systems - I did it all the time in Japan 10+ years ago.

by Rob on Nov 11, 2009 3:13 pm • linkreport

@ jfuh

Just because they wont use the same fares don't mean the entrances cant be in the same building.

They could be on different sides of the same building take the current silver spring station the building could be expanded further on both sides, the faregates, fare machines and station master's box could be moved around, so that the station masters box is in the middle and then on one side you have the red line and the other the purple.

I agree with the fare problem that could be a huge problem and could end it worst

If metro eventually ends up with metrorail, metrobus, metrolightrail + streetcars it would be a logistical nightmare figuring out all combinations of fares + the discounts on each of them.

Would lightrail fares be similar to bus or rail what about if metro ends up running streetcars for the various jurisdictions.

At a point like that it would just be easier to charge fares based on daily/weekly/monthly passes and let people use whatever way they choose to get wherever; other places around the world do it why not metro.

by Kk on Nov 11, 2009 5:15 pm • linkreport

The fare system is not complicated at all. London, for example, uses a zone based system, and the only stations with gates are downtown. So you enter downtown through a gate and when you leave in the suburbs theres no barrier...but you MUST tap out on the supplied sensor.

Such can be the same here. You enter the purple line via the standard gates, and when you leave on a platform without gates, you tap out on the supplied sensor.

People who dont tap out can be handled in the same way the system currently deals with people who leave the system through an open gate without tapping.

by J on Nov 11, 2009 8:45 pm • linkreport

The overhead would help solve an existing bottleneck.

Like too many other stations, S/S has *no* stairs to the platform. At afternoon crush hour, when a train unloads, you can read the Post while you wait to get down the escalators. If one is down, bring a book.

Added exits would be a big help.

by George B on Nov 12, 2009 2:31 am • linkreport


thanks for writing this.

by tony hausner on Nov 12, 2009 5:36 am • linkreport

I haven't seen any specifics on whether the "residential" will be condos or apartments.

We need more condos. I don't want to rent the rest of my life.

by blair rez on Nov 12, 2009 8:55 am • linkreport

I wonder how well everything will be integrated into the transit center. I'm also curious what this is going to look like. I hope the elevated structure for the Purple Line isn't just an ugly concrete viaduct.

For fare payment on the Purple Line, I think proof-of-payment would be the way to go. Scan your SmarTrip or insert money at a kiosk, and take a paper ticket. This could give a transfer discount similar to the bus. Do we know what is being considered?

Are there any renderings available for this thing, or is it too soon?

by Matthias on Nov 12, 2009 11:39 am • linkreport


MTA doesn't have any renderings of this yet that show the south end of the transit station. That is why it took me so long to put the pieces together in my mind, and why I hoped this post might be useful.
I hope MTA creates a good rendering soon. This is one of the most important stations on the line. The sooner we have a good rendering the sooner the community can become more engaged in giving good feedback on the look and the functionality.

by Wayne Phyillaier on Nov 12, 2009 11:52 am • linkreport

I'm not sure I understand the issue with the fare concepts. SmarTrip cards with fare readers on the Purple Line train cars, like on buses, would be the presumed payment method I would think. Like getting off the station now and getting on a bus. Metro and Purple Line won't be sharing the same platform, so I don't see the problem. Thanks for the post; it's very illuminating.

by Jeff on Nov 25, 2009 11:03 am • linkreport

The whole coercion of the ridership into WMATA's so-called smartcards is a topic I'd love for GGE to be discussing...

by george B on Nov 25, 2009 2:14 pm • linkreport

OK, I'll bite. What's your beef with a unified farecard system in a metropolitan area with three states and 5 or 6 counties all trying to run a coherent mass transit system? A unified farecard permits easier application of transfer discounts, and doesn't require any jurisdiction to charge any particular fee for its transit service-- Montgomery County is free to raise or lower its Ride On fares as it sees fit, while its riders can transfer easily to the WMATA system without the need for exact fares, or duplicate fare media, both of which were a real nuisance before.

by Jeff on Nov 25, 2009 4:09 pm • linkreport

Add a Comment

Name: (will be displayed on the comments page)

Email: (must be your real address, but will be kept private)

URL: (optional, will be displayed)

You can use some HTML, like <blockquote>quoting another comment</blockquote>, <i>italics</i>, and <a href="http://url_here">hyperlinks</a>. More here.

Your comment:

By submitting a comment, you agree to abide by our comment policy.
Notify me of followup comments via email. (You can also subscribe without commenting.)
Save my name and email address on this computer so I don't have to enter it next time, and so I don't have to answer the anti-spam map challenge question in the future.


Support Us