Wayne Phyillaier - Greater Greater Washington

Montgomery faces a hard decision with Bethesda tunnel

Mon, 27 Feb 2012 12:14:00 EDT

It'd be very expensive to keep the Capital Crescent Trail and the Purple Line in the same tunnel in Bethesda. The Maryland Transit Administration analyzed some options, but there is no silver bullet. The Montgomery County Council will have to make a tough choice between spending a lot of money or taking the trail out of the tunnel.

Photo by thisisbossi on Flickr.

The Capital Crescent Trail (CCT) runs in a former railroad tunnel under 2 buildings and Wisconsin Avenue in downtown Bethesda. Plans call for building the Purple Line in this tunnel, with a station under the Apex Building and elevators connecting to the Metro.

Officials have long promised to keep the CCT in the tunnel with the Purple Line, but the cost turned out to be much higher than expected.

The MTA looked at a number of alternative approaches:

The original plan: This design, the "locally preferred alternative," calls for lowering the floor of the tunnel to make room for an elevated CCT above the Purple Line. The Purple Line station would sit under the Apex Building, adjacent to the planned elevator connection to the Red Line.

Don't keep the trail in the tunnel: Another option would be to create a new trail alignment through Elm Street Park and along Bethesda Avenue. The tunnel would not have to be lowered, and the Purple Line would run alone in the tunnel. The station would be located in the same spot as in the original plan.

Don't put the Purple Line in the tunnel: The Purple Line could terminate east of the eastern end of the tunnel, letting the trail to remain in the tunnel. Passengers transferring to the Red Line would have to walk approximately ¼ mile to get to the new southern entrance to the Bethesda Metro.

Tear down and rebuild the Air Rights Building: Tearing down the Air Rights Building, above the tunnel, would make it possible to create a wider tunnel and fit the trail and train station side-by-side. It would require a slightly longer walk for transferring passengers than the original plan. It would also cost a lot of money to purchase and demolish the Air Rights Building on the east side of Wisconsin Avenue.

Have a narrower Purple Line through the tunnel: Several alternatives looked at using single track or gauntlet track in the tunnel. Station locations included placement in the original location or farther west in the Woodmont Plaza.

The County Council's Transportation and Environment Committee will discuss this issue on March 1.

The findings are disappointing to those of us hoped to escape making a very hard decision. All of the new alternatives for keeping the trail in the tunnel would either seriously degrade the level of service and operational capabilities of the Purple Line, or have an unreasonable cost.

The MTA draft report could do a bit more to persuade everyone by giving more details about why they rejected some alternatives. For example, the report says that operational models showed that the reduced transitway width alternatives didn't work, especially since the Bethesda station will be the end of the line.

But the report gives no information on the method and assumptions behind the simulations. It would be easier to accept the conclusions if they made those available for review. In any case, the MTA is likely right about this. I can find no examples of successful single-track operations for a terminal station with a short headway.

As much as I wish it were otherwise, we are back to the hard choice: either spend a now-estimated $50.9 million and take considerable construction risk to keep the trail in the tunnel in an overhead structure, or develop the alternative surface route across Wisconsin Avenue.

The right choice is to develop the surface route to the fullest extent possible. $50.9 million is simply too much money to spend to avoid one at-grade crossing for the trail. That cost will double the total cost of rebuilding the CCT, putting the whole trail project at much higher risk of being abandoned in these very difficult budget times.

Also, the elevated trail will involve a narrow switchback to climb above the tracks, and then run in a cage above the tracks. This will not be attractive to most trail riders, and certainly not inviting enough to justify spending $50.9 million.

There is also too much risk that digging under the APEX building will destabilize the entire building. The Silver Spring transit center turned into a fiasco because engineers underestimated the risk of a construction method. Nobody wants another mess like that along the future CCT in Bethesda.

Most likely, the council will decide against taking on the cost and risk that comes with keeping the CCT in the Bethesda tunnel. The political blowback from this decision will be intense; some of that has already started in the comments to the Washington Post's story about this report.

"Save the Trail" advocate Pam Browning and others are advocating for a third option: kill the Purple Line. But they have the tunnel vision that comes with thinking that CCT means "Chevy Chase's Trail." They care little about whether the CCT is ever completed into downtown Silver Spring, and would have us obsess about one trail crossing at Wisconsin Avenue while overlooking the many other at-grade crossings east of Bethesda that will be eliminated as a part of the Purple Line project.

A version of this article originally ran at Silver Spring Trails.

99 comments

Tunnel vision threatens the Capital Crescent Trail in Bethesda (Nov 4, 2011)
Montgomery Planning Board to hear recommendations about Capital Crescent Trail (Nov 16, 2011)
On-street Crescent Trail may be better for bikes and peds (Nov 17, 2011)
The Capital Crescent Trail should stay in its Bethesda tunnel (Nov 25, 2011)
Can the CCT bridge Wisconsin Ave in Bethesda? (Dec 15, 2011)

Can the CCT bridge Wisconsin Ave in Bethesda?

Thu, 15 Dec 2011 12:05:00 EDT

by Wayne Phyillaier

The design of the Purple Line might mean displacing the Capital Crescent Trail from its Bethesda tunnel. Some say that an at-grade crossing of Wisconsin Avenue will be too dangerous for cyclists and pedestrians. But are there any good alternatives?

I think that many hope that if only we make a strong commitment, bring creative imagination and bring professional expertise to the problem, then we can find an attractive alternate way. Maybe something that looks like this:

Rock Creek Trail bridge over Viers Mill Road.
Image from the National Transportation Enhancements Clearinghouse.

But the difficult part is the array of constraints presented by the crowded, urban space in Bethesda at Wisconsin Avenue.

Bridging the gap

A trail bridge with long ramps on either end will not fit into the space available along Bethesda Avenue and Willow Street without blocking critical business access and parking structure driveway entrances. And that's not feasible unless the county is willing to purchase the affected properties.

A conceptual bridge alignment. Click to enlarge.

The aerial map above shows the approximate length of the ramps for a trail bridge over Wisconsin Avenue that would be needed to meet ADA requirements.

A ramp up Bethesda Avenue must elevate the trail by approx. 18 feet above Wisconsin Avenue to allow clearance for traffic below and space for bridge deck supporting structure. Bethesda Avenue rises from Woodmont Avenue to Wisconsin Avenue and the bridge ramp must "chase the grade", adding another approx. 10′ to the total elevation gain needed on the ramp. If we assume a 5% ramp grade, then we will need a ramp that is 560 feet long on Bethesda Avenue.

We can shorten the ramp a little and still be ADA compliant by going up to a 7% grade that has flats at regular intervals. But even so the ramp will still be too long to avoid blocking driveways on either side of Bethesda Avenue.

One driveway on the north side of Bethesda Ave. Image from Google Street View.

Any ramp over several hundred feet long on Bethesda Avenue will block important driveway entrances, whether on the north or south side of the street. The problem is much the same for a ramp on the other side of Wisconsin Avenue at Willow Street. A ramp on Willow Street could be shorter, maybe a little less than 400′, since it would not be "chasing the grade". But it would still be much too long to avoid blocking critical driveway entrances on either side of Willow Street.

Switchback ramps or spiral ramps are shorter than linear ramps, but their footprints are at least twice as wide—there is no place that can accommodate the wide footprint of either a switchback or spiral in this area. And the question arises: "How many trail users will want to use such long, steep ramps if they can cross at-grade at a light?"

Can we find another location for the bridge and ramps?

If we explore other locations for a Wisconsin Avenue bridge crossing, we will get the same result: long ramps will create unacceptible blockages of driveways and business entrances. Elevated crossings at Elm Street, Miller Avenue, or Leland Street will create unacceptible blockages by the ramps on both sides of Wisconsin Avenue, and the routing of the trail on the east side of Wisconsin Avenue becomes very problematic for these alternate crossing locations. The "chasing the grade" problem is even more severe on Elm Street than it is on Bethesda Avenue.

An alternate approach is to consider "going aerial" for a longer distance than just on a bridge, so the ramps can be some distance away from the constraints near Wisconsin Ave. One obvious areal route would be to have a ramp at the Bethesda Trailhead adjacent to Ourisman Honda, go on aerial structure across the Bethesda Ave./Woodmont Ave. intersection, up Bethesda Ave., across Wisconsin Ave., and up Willow Street and then come down another ramp at Elm Street Park.

But the ramp at the Bethesda Trailhead would have to begin about 400′ south of Bethesda Avenue and very near the trail rest plaza to gain the elevation needed to clear Bethesda Avenue. The width of the ramp, at least 14′, would likely preclude also having a full width surface trail alongside the ramp. The local trail access to Bethesda Row along the trail right-of-way would be greatly compromised.

A long aerial structure would be very visually intrusive to the rest stop, Bethesda Row, the future Woodmont Plaza, all of Bethesda Avenue and Willow Street, and to Elm Street Park. Access to the Bethesda street grid and downtown destinations would be limited. If the only goal is to separate trail users from the Bethesda street grid, it might be better to reroute the CCT to completely bypass downtown Bethesda. But these approaches will not serve the many trail users who want good access to downtown Bethesda destinations.

Would a trail tunnel under Wisconsin Avenue fit any better?

Yes, a new trail tunnel would have much less impact on the Bethesda streetscape than would any trail bridge.

Conceptual tunnel alignment in Bethesda. Click to enlarge.

The conceptual sketch above shows the approximate location of portals (shown as red markers) into a new tunnel under Wisconsin Avenue. The aproximate lengths of the down ramps, or cuts, needed to take the trail elevation down to enter the tunnel at the portals is also shown.

Note that the down ramp, or cut, needed on Bethesda Avenue is less than half the length that would be needed for an up ramp to a bridge. There are two reasons why this is so. First, the existing elevation change along Bethesda Avenue helps for a down ramp, instead of forcing us to "chase the grade" for an up ramp. Second, we don't need as much elevation difference between the street grade and the top of the tunnel as we needed for clearance for the bridge (only maybe 12′ vs. 16′). I estimate a down ramp as little as 200′ long might work on the Bethesda Avenue end of the tunnel. That could just fit on the north side of Bethesda Avenue without blocking any existing driveways.

The down ramp on the Willow Avenue end of the tunnel would be a little longer, since there is no help from an existing grade on that side, and it would be too long to fit along Willow Avenue without blocking a driveway. The most feasible location for that down ramp would be as shown in the sketch, along the east side of 47th Street at Elm Street Park. A ramp should ideally continue east along the north side of Willow Street at the Park to avoid the trail turn at the tunnel portal, but I estimate that block of Willow Street is too short for the down ramp to fit.

The tunnel path shown in the drawing is only notional and can shift slightly to better suite construction conditions, but I think any "cut and cover" tunnel will need at least one bend in it to avoid buildings. A deep bore tunnel could be straighter if it goes under buildings, but it would be prohibitively expensive.

A tunnel can fit. Does that make it good?

This tunnel will fit into the Bethesda streetscape much better than will any elevated structure. The obstructive ramps would be much shorter, and the visual intrusion would also be minimal. But the tunnel will not be attractive to many trail users, and the cost will be high.

This is a long tunnel, and will not resemble an underpass which has a much more open feeling. The tunnel will not be as wide or high as is the existing trail tunnel under the Air-Rights Building. It will have curves and turns that will limit the sight lines to be much shorter than in the existing trail tunnel.

Trail users will not be able to see what is ahead of them in the tunnel when they enter. The perception and the reality of safety will be much lower than we have experienced in the tunnel under the Air-Rights Building. Many trail users (including me) will likely prefer to stay on an enhanced surface route.

The existance of this tunnel will preclude having a full width trail on the surface route. The tunnel down ramp on Bethesda Avenue will need at least a 14′ width, and that will take most of the width available so that only a minimal width sidewalk (6-8′) can remain alongside for the surface route. Similarly a 14′ wide down ramp adjacent to Elm Street Park will take the "easy" space between 47th Street and Elm Steet Park. Taking another 14′+ to also have a full width surface trail will have an unacceptible impact on the park. Trail users wanting to take the surface route instead of using the tunnel will be severely impacted by the existance of the tunnel.

Construction of the cut-and-cover tunnel will require moving all utilities along its path—and there will be many of them along these streets. The disruption to traffic on Wisconsin Avenue during construction will be considerable, and construction incentives to minimize the time of this disruption will impact cost. I do not have the experience needed to estimate the tunnel costs, but it is a safe bet it will be high.

I believe a new trail tunnel under Bethesda Avenue will compare very poorly with the tunnel design that has been proposed for the trail with the Purple Line under the Air-Rights Building. It is a bad idea, largely because it will obstruct a full width, off-road trail on the surface route that many of us would choose to use instead of the tunnel.

What is the best way forward?

WABA has stated its position on the way forward in its Quick Release blog.

"�as advocates for the best possible trail and crossing, WABA asks that the county take steps to evaluate the importance of a grade-separated crossing, account for the importance of grade-separation to trail usage and safety by including an alternative grade-separated option, and clearly define the proposed enhancements that would be included in the on-street option that would make it more than a fallback cost-savings at the expense of trail users and to the detriment of the project."

My opinion about the best way forward differs from WABA's.

I think there is little value in exploring an alternative grade-separated option much further. The many constraints of the Bethesda urban design space will make a new trail bridge not realistically feasible. The best likely new trail tunnel will be too unattractive to many trail users and will physically obstruct our best surface trail route.

Continuing to pursue an alternative grade-separated crossing will only take us to more dead ends. We should instead focus on getting the strongest possible commitment from the County that if a decision is taken to not keep the CCT in the tunnel under the Air-Rights Building, then the features recommended for the enhanced surface route in the Planning Board letter will be implemented. The most important of these enhancements is to provide a protected Wisconsin Avenue crosswalk by restricting motor vehicle turning movements.

With the commitment of the county, we can design a safe, direct connection for the CCT that is on-street. We should push for the best design possible as we focus on building a better trail for the future.

33 comments

Changes mean more Purple Line and trail grade-separation (Sep 21, 2011)
Montgomery Planning Board to hear recommendations about Capital Crescent Trail (Nov 16, 2011)
The Capital Crescent Trail should stay in its Bethesda tunnel (Nov 25, 2011)
Tunnel vision threatens the Capital Crescent Trail in Bethesda (Nov 4, 2011)
On-street Crescent Trail may be better for bikes and peds (Nov 17, 2011)

Tunnel vision threatens the Capital Crescent Trail in Bethesda

Fri, 04 Nov 2011 09:14:00 EDT

by Wayne Phyillaier

While fighting hard for the full, timely build-out of the Purple Line, advocates of greater and greener mobility in our region also must work to save the tunnel alignment of the Capital Crescent Trail (CCT) through downtown Bethesda, which is key to making bicycling there safe and attractive for the long term.

The CCT underneath Wisconsin Ave. in downtown Bethesda. Photo by thisisbossi on Flickr.

The Montgomery County Planning Board is seriously considering recommending removing the trail from the Bethesda Tunnel as the Purple Line is built to avoid the cost of widening the tunnel to accommodate both rail and trail (see the WashCycle for good analysis).

Board members took a walking tour of the trail to gather background information yesterday. The Maryland-National Capital Park and Planning Commission's Capital Crescent Tour document (PDF) describes the walking tour agenda, and presents the detailed cost analysis report.

The public will have a chance to weigh in at the the Planning Board's Nov. 17 work session. Trail and cycling advocates need to sort through the cost issues and be ready to present thoughtful and convincing arguments by Nov. 17.

"Save the Trail" advocates' immediate reaction to the report is that the CCT will be destroyed if trail users are forced to use the alternative alignment that crosses Wisconsin Avenue at-grade:

Two alternatives for the CCT in Bethesda. Image from the Planning Board.

This at-grade crossing of a busy highway takes away the safety and convenience that make the trail so attractive. I made the case for keeping the trail in the tunnel when the estimated cost of doing so was $60 million (December 2010). With the cost now approaching $100 million, the case becomes harder to make and the tunnel route is at risk.

~~Maintaining the trail parallel to the light-rail tracks through Bethesda Tunnel must be our paramount issue.~~ The trail is an important element of the Purple Line plan. But making the Bethesda tunnel the paramount issue misses the point. Opposing the Purple Line in order to save the trail would be counterproductive: the definition of "tunnel vision". It is worth referring to this map:

The completed CCT will link two large urban centers and will connect to the Metropolitan Branch Trail to complete a major regional trail system.

If our goal is to have a regional trail, then we must remember that there is an approximately 1.5-mile section at Silver Spring that is incomplete, and remains on-road. There are seven at-grade crossings of streets at traffic lights on the existing Georgetown Branch Trail east of the Bethesda Tunnel, including three crossings of multi-lane state highways (Connecticut Avenue, 16th Street, and Colesville Road).

The rebuilt trail alongside the Purple Line would replace all 1.5 miles of on-road route with a completely off-road trail into downtown Silver Spring. All seven at-grade crossings at lights would be replaced by the rail line and trail tunneling under, or bridging over, these busy roadways. Prospects for ever completing the trail and removing these seven at-grade crossings east of Bethesda are very poor unless the Purple Line is built as planned.

Losing the Bethesda Tunnel would be a significant loss for the Capital Crescent Trail. We need to fight to save it. But the trail will be more continuous and safer when rebuilt alongside the Purple Line than it is today, even if we lose the Bethesda Tunnel. Killing the Purple Line would do more harm than good to the CCT's future viability.

Editor's note: One paragraph in this post was inadvertently changed during the editing process. The offending sentence has been struck through, and a new sentence added to clarify the meaning. We regret the error.

43 comments

Urban bike trails aren't just for recreation (Jan 5, 2009)
Changes mean more Purple Line and trail grade-separation (Sep 21, 2011)
How the Purple Line will fit through the Silver Spring Transit Center (Nov 11, 2009)
Sign the Purple Line petition (Sep 16, 2008)
Time to fast-track the southern Bethesda Metro entrance (Nov 2, 2010)

Changes mean more Purple Line and trail grade-separation

Wed, 21 Sep 2011 15:48:00 EDT

by Wayne Phyillaier

Maryland's MTA is removing the only grade-crossing between Silver Spring and Bethesda in its plans for the Purple Line. This will improve the experience of trail users on the adjacent Capital Crescent Trail and could improve reliability of the light rail line.

Revised MTA plans for the Lyttonsville area. Click for full map.

Between Silver Spring and Bethesda, the proposed Purple Line will run on an abandoned railroad line. This line has been a bicycle/pedestrian trail for some time, and an improved trail will be included as part of the Purple Line project.

Lyttonsville is an industrial and residential neighborhood near Silver Spring. The area is located north of East-West Highway, between the CSX tracks (MARC Brunswick Line) and Rock Creek. Here, the Purple Line diverges from the active CSX right-of-way to run on the abandoned Georgetown Branch.

The MTA briefed local residents on the new plans at a neighborhood work group meeting last week. Some significant changes have been made to plans in the area. The primary difference is that the future CCT and the Purple Line work yard are flipped in their positions. Now, the CCT is proposed to run along the north side of the Purple Line transit/trail corridor from Rock Creek to the CSX corridor.

One of the major benefits of the Purple Line to trail users will be the inclusion of grade separation at all intersections. Currently, cyclists have to cross traffic 3 intersections and one driveway between Bethesda and the eastern end of the trail in Lyttonsville. Plans had already included adding grade separations at Connecticut Avenue and Jones Mill Road.

With the proposed bridge over the tracks for Stewart Avenue and the closure of the driveway, cyclists and pedestrians will be able to cycle from the Silver Spring Transit Center to Woodmont Avenue in Bethesda without crossing a street.

Other changes are described below:

At Rock Creek, the CCT remains on the north side of the light rail tracks. The prior plans called for the CCT to switch from the north to the south side of the tracks at the Rock Creek trail bridge. The new plan holds the trail on the north side. The trail bridge is simpler since it does not have to twist under the Purple Line bridge.

The access ramp from the CCT down to the Rock Creek Trail would be like before, except that it would be built on the north side of the berm. This access ramp is still under discussion between MTA and M-NCPPC. There are concerns about cost and the impact on the trees on the side of the berm, and a decision could be taken to just continue to use the existing connection on Susanna Lane.

At Grubb Road, a new bridge will carry the access path across the Purple Line tracks to the CCT on the north side. The drawings show a long switchback ramp to provide the elevation needed for the new access bridge. But the access path is roughly along the same alignment as the old Brookville Road bridge that crossed over the B&O tracks here long ago.

The railbed elevation is already well below the elevation the access path has now, and I believe the extent of the switchback ramp shown in the drawing is grossly overstated. When I asked Purple Line project manager Mike Madden about this, he indicated the ramp in the drawing was only conceptual and was not based on any elevation measurements, so it is likely overstated in the drawing.

Along Brookville Road, MTA is proposing an access trail paralleling the main trail. The drawing shows two trails alongside each other along the south side of Brookville Road. The main CCT is the wider trail (to be 12 feet wide) that is next to the Purple Line tracks. It goes under the Lyttonsville Place bridge and under the relocated Stewart Avenue bridge.

The access trail is the narrower trail (to be 8′ wide) that is adjacent to Brookville Road and between Brookville Road and the main CCT. It serves as a Brookville Road sidewalk and also gives access to the main CCT between the Lyttonsville Place and Stewart Ave. bridges. The access trail crosses Lyttonsville Place and Stewart Avenue at-grade at the north end of the bridges.

At the Lyttonsville station, the CCT is on the north side. Under the old plan, the Purple Line tracks and station were on the south side of the rail yard, and the trail was on the south side adjacent to the industrial lots. Under the revised proposal, the trail and Purple Line have been moved to the north side, closer to Brookville road.

Additionally, MTA is considering moving the transit station location further east, closer to Stewart Ave. This would place the station closer to the entrance to the Walter Reed Annex, the area's largest employer.

A bridge at Stewart Avenue, will be constructed. Part of Stewart Avenue will be shifted to line up with the main entrance to the Walter Reed Annex and to have Stewart Avenue cross over the CCT and the Purple Line on a new bridge. The old plan had both the trail and transit crossing Stewart Avenue at-grade. This change would remove the only at-grade roadway crossing on the CCT and Purple Line between Bethesda and Silver Spring, making the rebuilt trail 100% grade separated.

A relocated trail bridge over the CSX tracks. The CCT would cross over the CSX tracks on a new bridge similar to the old plan, but the bridge would be shifted to the north closer to Kansas Avenue. This would not be a significant change for the trail, but does reduce the impact of the Purple Line on Talbot Avenue. Talbot Avenue could remain as a two way street as it is now, and much less r.o.w. would need to be taken from the several homes on Talbot Avenue.

Overall I consider flipping the CCT from the south to the north side to be roughly an even trade for trail users. Access will be slightly more inconvenient from neighborhoods to the south, but easier from the neighborhoods and businesses on the north. The trail will be closer to Brookville Road—with more traffic noise. But it will also have a new grade-separated crossing at Stewart Avenue.

Much like the lengthy discussion of north versus south in Bethesda/Chevy Chase, your preference will be determined largely by whether you live or work on the north vs. the south side of the corridor. As always, much will depend on the details to be developed during the next design phases.

The MTA comparison of the impacts shows that the overall footprint of the project is little changed through this area. A few feet of r.o.w. would be taken on the north side, but a comparible area is spared on the south side. The notable exceptions are the parking structure for the Purple Line maintenance yard employees that would be built where the car storage lots are now, and the realigned section of Stewart Avenue that would be built where the landscaping stone storage yard is now.

Some residents from neighborhoods on the south side of the project are making claims that the new plan will impact them much more than the older plan. But I don't buy it. The most active part of the project, the Purple Line main track and station, are moved farther from the south side neighborhoods. The storage tracks and maintenance building are only a few feet closer to the south side residences than in the older plan, and still have good separation from the residences.

The parking structure will be closer to the Claridge House high-rise, but will a parking structure used by the approx. 200 employees really be that much worse than the car storage lots and landscaping business lots that are there now? Detailed noise studies have been promised by MTA.

23 comments

How the Purple Line will fit through the Silver Spring Transit Center (Nov 11, 2009)
A timeline of the Metropolitan Branch Trail (Aug 27, 2010)
Despite rival visions, change is coming to Chevy Chase Lake (Jun 14, 2011)
Klingle Valley to get 10-foot trail, lights, trail connection (Jan 13, 2011)
Residents support the Purple Line at Bethesda/Chevy Chase hearing (Nov 19, 2008)

Despite rival visions, change is coming to Chevy Chase Lake

Tue, 14 Jun 2011 15:40:00 EDT

by Wayne Phyillaier

Chevy Chase Lake is where the Interim Capital Crescent Trail crosses Connecticut Avenue. This area is likely to soon transform into a vibrant urban node, but the magnitude of the change is still up for debate.

Crossing Connecticut Ave. Photo by author.

The area is now a collection of small shops including Starbucks, two gas stations, a supermarket, a lumber yard, and the 13-story Chevy Chase Land Company office building containing City Bikes. Residential buildings on Chevy Chase Lake Drive are also part of the sector. Parking lots cover much of the area.

Two big projects are coming that will change the trail and Chevy Chase Lake: the Purple Line and the Chevy Chase Lake redevelopment.

The Purple Line

The safety and convenience of crossing Connecticut Avenue on the CCT will improve greatly when the Purple Line is built. The plans call for the CCT to cross Connecticut Avenue on a trail bridge alongside the Purple Line light rail bridge.

The trail will have a direct connection to the elevated station platform on the east side of Connecticut Avenue. The MTA aerial photograph below shows the route of the Purple Line and CCT through Chevy Chase Lake, and the location of the station platform. More aerial maps are available at MTA's Purple Line website that show better detail.

Future CCT bridge crossing of Connecticut Ave.

The CCT will be elevated through much of the Chevy Chase Lake sector, on the bridge over Connecticut Avenue and at the transit station platform, and on the trail ramps that approach from both sides. This may become important, because future development may bring much local pedestrian activity to the sector. The trail elevation will allow us to keep trail/local pedestrian conflict areas limited to the designated trail access points.

Two competing visions for the Chevy Chase Lake redevelopment

On April 27, the Chevy Chase Land Company (CCLC) presented its vision for Chevy Chase Lake to the public at the National 4-H Youth Conference Center. That presentation is available as a YouTube video. Several illustrative drawings from that presentation were also shown in the Purple Line Progress Report that PLN President Ralph Bennett presented to the Affordable Housing Conference of Montgomery County on May 9.

Chevy Chase Land Company illustrative site plan.

The CCLC vision is for transit oriented development of up to 4,000,000 square feet of mixed commercial/residential uses, with about 3/4 of the development being residential (up to 3000 residential units). Building heights transition from 6 stories high at the edges to up to 19 stories high near the center. The plan features a local street grid with extensive public spaces, a public plaza at the Purple Line station, and neighborhood oriented ground level retail.

CCLC illustrative drawing of proposed Main Street public spaces.

Looking west on the proposed Main Street. (The arrow at the left side marks the CCT ramp up to the light rail station and bridge over Connecticut Ave.

Montgomery County planning staff released a narrated video to present their very different recommendations for the new Chevy Chase Lake sector plan on June 8, 2011. That video is available on their Chevy Chase Lake webpage.

The planning staff is recommending to the Planning Board that a smaller portion of the Chevy Chase Lake Sector be rezoned to allow slightly over 1,000,000 square feet of mixed use (commercial/residential) development, 250,000 square feet now and another 800,000 square feet to be allowed when Purple Line construction begins.

This is only slightly greater than that approved now under the current zoning. Building heights would be limited to 65 feet, only about six stories. (The CCLC building already on the site is 13 stories high, and a residential building now stands immediately south of the site alongside the Columbia Country Club that is 18 stories high.)

The CCLC and the Montgomery County planning staff visions differ greatly on the density to ultimately be allowed at Chevy Chase Lake. The planning staff recommends only a marginal increase in the number of residential units over that already approved. The Montgomery County planning staff will hold a public meeting to present its recommendations at 10 am to noon Saturday, June 18 at the Chevy Chase Village Hall, 5906 Connecticut Avenue.

Does the density at Chevy Chase Lake matter to trail users?

The major features of the CCT itself will not be impacted much by the different levels of density being proposed for Chevy Chase Lake. The trail ramps and bridge will not change, and most of the trail will be separated from the local pedestrian activity by being on elevated structure.

Both the CCLC and the planning staff visions call for a public plaza at the Purple Line station, and the CCT would pass through that plaza area. A higher density would make this a more pedestrian active area. But careful design of the pedestrian crossing paths in this plaza will be mandated by the need to keep pedestrians clear of the light rail activity that parallels the CCT. Pedestrian crossings will likely be focused to only one or two points and this will minimize the trail/pedestrian conflict areas.

A higher density at Chevy Chase Lake will have a bigger impact on trail users when they leave the primary trail in this area. Higher density with taller buildings makes it more likely we will have a good local street grid with public spaces, like that envisioned by CCLC.

If the building height is limited to 65 feet as called for by planning staff, then a developer must cover more available land with low buildings to get up to the floor-area ratio allowed by the zoning. A smaller project will also give less economic justification to set aside space for wide streets and public spaces, and the County will have less leverage to require these amenities as a condition for the project.

There may be less local pedestrian and motor vehicle traffic in a smaller project, but the local street grid may be more limited, streets may be narrower, and space set aside for public use may be smaller so biking conditions could feel congested even with less traffic. Smaller may not be better for bicycle friendly conditions overall.

Trail users don't have a strong reason to enter the discussion of density at Chevy Chase Lake to protect or advance the CCT. We have other reasons to join the discussion about how our region will grow, however, as members of the community. Trail users are likely to have diverse views about "smart growth" and "transit oriented development".

I'm joining the discussion as an individual in support of a higher density at Chevy Chase Lake. Opportunities for transit oriented development are very limited. We have a strong need for more residential housing to balance with jobs in the Bethesda area—especially for housing close to the National Naval Medical Center, where up to 2500 new staff positions are coming with BRAC. If we won't allow more residential housing units here, then where else should it go that is better?

And besides, I want one of those residential units. I'd love to live in a place like this.

31 comments

Residents support the Purple Line at Bethesda/Chevy Chase hearing (Nov 19, 2008)
Changes mean more Purple Line and trail grade-separation (Sep 21, 2011)
Does redevelopment along transit have to be 18 floors? (Jun 15, 2011)
How the Purple Line will fit through the Silver Spring Transit Center (Nov 11, 2009)
Town of Chevy Chase takes ball, goes home, calls referee a cheat (Jan 21, 2009)

Silver Spring bike station gets planning money

Wed, 03 Nov 2010 12:17:00 EDT

by Wayne Phyillaier

WashCycle alerted us to a TBD article about the Silver Spring Park development project, recently approved with the requirement that the developer commit money to the Silver Spring bike station.

Location of the future Gene Lynch Urban Park. From plans presented to the Planning Board.

From the article:

To make up for the remaining public space requirement, developers will give $152,728 to Maryland-National Capital Park and Planning to pay for a bike station at Gene Lynch Urban Park, which is adjacent to the Silver Spring Transit Center.

The $153K funding commitment to the bike station will surely not be the only funding needed to complete the station. The M-NCPPC staff recommendation is for these funds to be used for development of "architectural schematic design drawings". But this commitment is an important step forward.

The bike station will be located in the proposed park, at the corner of Colesville Road and Wayne Avenue. This location is across Wayne Avenue from the Sarbanes Transit Center, currently under construction. It's located near several bike facilities, including the proposed Capital Crescent and Metropolitan Branch trails.

Crossposted at Silver Spring Trails

5 comments

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

Wed, 11 Nov 2009 13:43:00 EDT

by Wayne Phyillaier

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.

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 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. Source: www.purplelinemd.com (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 www.purplelinemd.com 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.

"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.

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 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.

15 comments

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