Posts Tagged ‘Bethesda Tunnel’

Is the Future CCT headed for gridlock?

Friday, January 18th, 2013

Preliminary Engineering by the Maryland Transit Administration (MTA) for the Purple Line and Future CCT is nearing completion. MTA has begun its second round of neighborhood work group meetings to present the next level of design to the public. Purple Line/CCT design features were presented for the Bethesda Station area on December 18, 2012 and for the Lyttonsville and Woodside Station areas on January 16, 2013. The most recent powerpoint presentations, sketches and maps for those areas are available now at the MTA website.

A sample of the information available at the MTA website for neighborhood work groups Bethesda, Lyttonsville and Woodside:

Purple Line and CCT bridges over Rock Creek
Proposed Purple Line and CCT bridges over Rock Creek
(source: MTA at www.purplelinemd.com)

Partial map of Future CCT at Rock Creek
The future Purple Line and CCT alignment at Rock Creek
(see MTA Lyttonsville Map for a more complete view)

The new MTA drawings show some changes from prior CCT plans, including:
1) The new 5-7′ wide sidewalk alignment through the Bethesda Tunnel, with the main trail shunted to the surface route (surface route not shown – that is under design by MCDOT),
2) The north-side location for the switchback connection to the Rock Creek Trail,
3) A new underpass alignment under the Purple Line tracks that is closer to the Rock Creek bridges,
4) A trail bridge over the CSX tracks that is further north from the Rosemary Hills Elementary School, and
5) A new, grade separated crossing under the east end of a proposed new Talbot Avenue Bridge.
These changes reflect some difficult trade-offs, but by-and-large can result in a high quality off-road trail from the center of Bethesda into the center of Silver Spring. While the decision to take the trail out of the Bethesda Tunnel and across Wisconsin Avenue at-grade has been a disappointment, the trail would have only one other at-grade crossing between Bethesda to downtown Silver Spring (at relatively quiet Stewart Avenue in Lyttonsville). At-grade crossings at three state highways (Connecticut Ave., 16th Street, and Colesville Road) on today’s Georgetown Branch Trail would be eliminated.

All of this planning is in serious danger of going onto the shelf, with no progress for building either the Purple Line or for completing the CCT for many years to come!. The facts:

  • All funding for Purple Line planning ends in 2014, and there is no funding available for construction to begin.
  • To avoid a shut-down of work, the state must submit an application for a “Record of Decision” to the FTA this summer to get federal construction funding. The application must include a credible financial plan to show how the state will meet its proposed 50% share of the construction costs.
  • The state transportation trust fund has been depleted and the state has no money to start any new highway, bridge or transit projects. The state cannot submit a credible financial plan for its share of the Purple Line unless a serious transportation funding package is approved by the state legislature now that will restore the Transportation Trust Fund in the immediate future.

The impact of the uncertainty in state funding for Purple Line upon completion of the CCT is already showing – with the recent accouncement that funding to build the CCT is being delayed: See Montgomery County projects tied to Purple Line delayed

If the governor and state assembly do not act in this legislative session, it will likely be many years before the transportation funding issue is addressed again in any substantial way. Next year is an election year and little will get done that involves political courage. The Purple Line will lose its place in line for federal construction funding. It could be many years before the project can be revived, and much of the design work will then need to be updated.

If the Purple Line project stalls, progress on completing and paving the Future CCT between Bethesda and Georgetown will also stop. We will not get the right-of-way in the CSX corridor that is crucial to completing the trail.

There is no alternative trail alignment for an off-road trail into downtown Silver Spring that does not require using CSX right-of-way in several places. But CSX has a strong general policy of not allowing any trail uses within its right-of-way. Purple Line project manager Mike Madden confirmed in an email exchange with me on November 26, 2012 that MTA had sent Purple Line plans to CSX for comment last fall, and CSX had responded in a letter to MTA to indicate it would not grant right-of-way for any trail use. MTA responded in turn with a letter to CSX to request that an exception be made for the state Purple Line/CCT project. Mike Madden told me at the 16 January Lyttonsville/Woodside neighborhood work group meeting that CSX has not yet responded to this request.

CSX right-of-way needed at 16th Street Bridge
The grade-separated trail crossing under the 16th Street Bridge
is one of several places where CSX right-of-way is critical
(source: MTA at www.purplelinemd.com)

The state has considerable leverage it can use to bring CSX to the negotiating table regarding right-of-way for the Purple Line and CCT. CSX has many business interests statewide that are before the state for consideration, including requests for increasing its freight infrastructure capacity along its Brunswick Line. CSX cannot easily brush the state request for CCT right-of-way aside so long as the state makes the CCT an integral part of its high priority Purple Line project. But if the Purple Line project stalls, CSX right-of-way negotiations with the state will stop. Montgomery County has no leverage to bring CSX to the negotiating table for a trail-only project.

Paving the existing Georgetown Branch Trail between Bethesda and Lyttonsville will also likely remain gridlocked without the Purple Line, for several reasons:
1) The county council will be extremely reluctant to approve funding to pave the existing trail so long as there is any hope that the trail will be torn up and rebuilt for shared use of the corridor with transit in the not-to-distant future. Transit use has always been proposed for this corridor since the county bought it in 1988 – in fact the corridor would never have been purchased by the county if not for this future shared transit/trail use. Even if the Purple Line stalls, the need for better rapid transit between Silver Spring and Bethesda will only continue to grow. Neither East-West Highway nor Jones Bridge Road can be expanded to have the dedicated transit lanes that are essential for “rapid” transit on these congested roads, at any reasonable cost and impact. This Georgetown Branch transportation corridor will continue to be the only, and obvious, choice for better east-west rapid transit, whether as light-rail or as Bus Rapid Transit. Trail supporters cannot reasonably expect that this corridor will be surrendered to them for exclusive trail use if the Purple Line stalls.
2) Transit supporters will vigorously oppose placing anything in the Georgetown Branch corridor that may make it politically more difficult to advance transit in the future. I believe some limited trail development is worthwhile and should proceed in this corridor – I was in the lead in advocating for opening the Rock Creek Trestle in 2003. But I cannot dispute that “Save the Trail” advocates have used “we got here first” to build opposition to transit in the corridor, with no regard to the fact that the trail would not exist today if not for the promise of future shared transit and trail use.
3) There will be significant oppositon to paving the trail from local neighorhoods and other users. Pam Browning, past president of “Save the Trail”, was on record in opposition to paving the trail unless it is done without replacing the existing gravel path and without cutting any trees. Those conditions are, of course, impossible to meet. There are many other local residents, joggers, and recreational cyclists who would like to see the Interim CCT stay as it is – uncrowded and natural. They fear paving will open the CCT to speeding cyclists.

Trail users should be very concerned that the Purple Line is in danger of stalling because the state Transportation Trust Fund is running on empty. If the project stalls then completing and paving the future CCT will stall along with it. If that prospect bothers you and you live in Maryland, then now is the time to contact your Maryland State Representatives and urge them to fix the Transportation Trust Fund.

Sidewalk through tunnel is likely

Wednesday, June 13th, 2012

WABA Board Member Jim Titus reports in a post at WashCycle that MTA has announced they are finding it possible and cost effective to build a 5 foot wide sidewalk through the Bethesda Tunnel alongside the Purple Line.

This is welcome news. This sidewalk could provide an alternative to crossing Wisconsin Avenue at-grade for pedestrians using the CCT. It also will provide easy access to the Purple Line platform and the new South Metro Station Entrance for many transit users. The sidewalk will be too narrow and too heavily used by pedestrians for safe use by cyclists.

Jim Titus reports that MTA expects the county to bear the cost of this sidewalk, as part of the county’s agreement to pay for the CCT. But the county is already commited to spending several million dollars to build a full width trail separated from motor vehicle lanes, down Bethesda Avenue and Willow Lane as an alternative CCT route to the Bethesda Tunnel.

It is unfair for MTA to consider this proposed 5 foot sidewalk as only a part of the trail, and not as an integral part of the Bethesda Purple Line station. There will be more people using the Purple Line platform every day than now use the trail in an entire week. We can expect the majority of users of this proposed 5 foot sidewalk to be transit users accessing the Purple Line platform and the new South Bethesda Metro Entrance from the many residences, schools and businesses on the east side of Wisconsin Avenue. Providing access to the Purple Line platform should be a responsibility of MTA, and MTA should not be demanding that scarce trail funds be used for this purpose.

T&E Committee picks plan “B” (or “E”)

Thursday, March 8th, 2012

The Montgomery County Council T&E Committee took up the difficult issue of rebuilding and completing the Capital Crescent Trail with with Purple Line for the second time at its worksession on the CIP budget today. The Committee voted by 3-0 to accept the recommendation from MTA and the Council staff that the cost and risk of keeping the trail in the Bethesda Tunnel by stacking the trail over the top of the Purple Line was too high. The T&E Committee members appeared to be at least as concerned with the high construction risk as with the $50.1M estimated cost. Representatives from MCDOT testified that they had reviewed the MTA report, and concluded that MTA was not overstating the high risk that the Apex building would be destabilized by the digging needed to place the trail over the top of the Purple Line in the tunnel.

The T&E Committee accepted the staff recommendation to program trail construction at the funding level that is shown in the meeting packet. The total estimated baseline cost of rebuilding the CCT along the alternative surface route across Wisconsin Avenue and completing the CCT into Silver Spring is $48.1M. Of that, staff recommended that only $27.6M be programmed into the FY13-18 CIP. This is the amount needed to rebuild the CCT in the Georgetown Branch Corridor alongside the Purple LIne from Bethesda to Lyttonsville, with construction to begin in 2016 to coincide with the estimated Purple Line schedule. The remainder, to build the CCT down the CSX corridor from Lyttonsville into downtown Silver Spring, would be deferred until FY19-20, to complete the trail by 2020. The section of trail along the CSX corridor will be on the opposite side of the CSX tracks as the Purple Line, and its construction can begin later because it does not need to be as closely coordinated with Purple Line construction as in the Georgetown Branch corridor.

Council Staff Director Glen Orlin pointed out that although this level of funding assumes the trail would be built following the MTA “Alternative B” plan using the surface route along Bethesda Avenue/Willow Lane/Elm Street Park, this level of funding would also support building the trail through the tunnel following the several alternative plans that would leave the trail in the tunnel, either if the width of the Purple Line is restricted in the tunnel by single-tracking or if the Purple Line does not enter the tunnel. In particular the “Alternative E” that would have the Purple Line platform under the Apex Building but use a single track or gauntlet track in the tunnel has not been entirely ruled out.

Bruce Johnston, MCDOT Division of Transportation Engineering, testified that MCDOT had not yet fully accepted the MTA conclusion that singe-tracking the Purple Line in the tunnel would have an unacceptible impact on the ability to maintain the six-minute headways the system needed. In particular, MCDOT wants a more complete showing from MTA of why they believe a 5 minute “dwell time” will be required at the Bethesda platform to make train schedule adjustments.

Summing up, the T&E budget recommendation means that keeping the trail in the tunnel by “Alternative A”, over the top of the Purple Line, is being ruled out as too risky. “Alternative B”, taking the trail across Wisconsin Ave. on an at-grade alternative route, is being budgeted. However several other options that would build the trail through the tunnel, especially “Alternative E” that would use a single-track, are not precluded by today’s budget recommendation.

Other lesser recommendations from the T&E Committee today:

  • No to having lighting along the entire trail. Yes to “spot lighting” where needed such as at trail access points.
  • No to emergency call boxes along the trail. Many trail users carry cell phones that serve that purpose.
  • Yes to enhanced landscaping between the trail and the neighborhoods. Landscaping between the trail and the Purple Line tracks is being budgeted elsewhere, as a Purple Line expense.

The T&E Committee budget recommendations will now go to the full Council for final reconciliation this spring. The Council usually gives much weight to committee recommendations, but the budget may change before final adoption by the full Council.

Tunnel expectations

Sunday, March 4th, 2012

The local news media is reporting on the Montgomery County Council’s reaction to the recent assessment from MTA that keeping the CCT in the Bethesda tunnel will carry very high cost and risk. The Gazette has one of the best reports at Underground Capital Crescent Trail crossing would cost $51 million. The Gazette article gives these reactions from two of the Councilmembers on the T&E Committee:

“I think it is a very serious change from what all of us had expected when we conceived of the trail going through the tunnel,” said Montgomery County Council President Roger Berliner (D-Dist. 1). ….

and:

Councilwoman Nancy Floreen (D-At large), a member of the transportation committee, said the county made a commitment to keeping the trail inside the tunnel, and she stands by that commitment.

“The crossing at Wisconsin Avenue is incredibly dangerous,” she said. “This conversation has been consistent over the years that the trail would be protected at all costs. There is a cost, that’s true, but one that the county will have to face.”

Contrary to what we have come to expect in recent years, there was no expectation promise at the start that the trail would remain in the tunnel. The first Master Plan showed uncertainty whether it was feasible to do so, at any cost. The 1990 Georgetown Branch Trolley Master Plan is available online at www.montgomeryplanning.org. This Master Plan does emphasize the goal of keeping the trail in the tunnel. It illustrates how this might be done by this sketch at page 52:

Sketch of double track trolley in the Bethesda Tunnel

Note the 1990 Master Plan shows the trolley as
double track through the Bethesda Tunnel

But the sketch above is given in the Master Plan as an aspiration, not as an expectation. From the text that comes with the sketch, .p. 51-53 (emphasis mine) :

“In order for hikers, bikers and trolley patrons to safely and conveniently use both the trolley platform and the hiker/biker trail within the Bethesda Station, the Plan recommends that the station design should include an extension of a concourse through the platform area in order to provide adequate trail width and safety. An illustration of this concept is shown in Figure 21. Further study of both the physical and operational elements is necessary during the design phase of the trolley/trail to determine the feasibility of the recommendation.

It is interesting to read the 1990 Master Plan, because the trolley described in the Master Plan is very different from the way the Georgetown Branch Trolley concept is usually described today. Purple Line opponents often assert that the Georgetown Branch Trolley was promised to be an entirely single-track trolley that would have a minimal impact on neighborhoods and the trail. But the 1990 Master Plan shows a trolley with characteristices that are very different from that nostalgic vision, including:

  • Very significant double track sections, including at all five stations. Nearly 30% of the “single-track” trolley was planned to be double-track from the start, including at some of the most constrained areas along the corridor such as through the length of the Bethesda tunnel.
  • Projected headways of 6 minutes, the same as for the Purple Line.
  • Travel times between Silver Spring and Bethesda of 9-10 minutes, compared to 8 1/2 minutes for the Purple Line.
  • Track/trail typical profiles that show trail separation distances from the near track that are very similar to that of the Purple Line.
  • Preservation of right-of-way for possible future conversion of all single-track sections to double-track, if required by future growth in ridership.

Assertions that the Georgetown Branch Trolley had been promised to be a slow, occasional neighborhood trolley running quietly through this corridor are bogus.

I can recall going to Purple Line meetings years ago and hearing the MTA present the concept for keeping the trail in the tunnel. MTA would regularly warn that although the concept might be feasible, we would not know for certain until more detailed measurements had been taken in the tunnel and the design studies had advanced beyond the early concept stage. Keeping the trail in the tunnel was usually presented as an aspiration, not as a clear and certain promise.

But as time passed, there was a shift in the way the tunnel design concept was presented. I first took note of it when MTA briefed the concept of the trail in the tunnel to the County Council on October 21, 2008. The MTA appeared to me to be less tentative about the feasibility of the concept than it had been in the past. See the concept sketch from that briefing below:

Source: MTA briefing to County Council, Oct. 21, 2008

On Sept. 13, 2010 the MTA briefed the CCCT and guests on the CCT with the Purple Line. Maybe I only heard what I wanted to hear, but again I do not recall that the MTA was tentative about keeping the trail in the tunnel at that meeting. The MTA presented details on a switchback ramp concept to elevate the trail over the Purple Line, and I posted my view that this ramp would be very unattractive to trail users at Bethesda tunnel west. But I hardly questioned whether the underlying concept of stacking the trail over the Purple Line in the tunnel was feasible.

New images of the Bethesda Tunnel began to appear that showed an attractive trail over the Purple Line. I posted one of the images at Bethesda tunnel, revisited:

A conceptual drawing of the Bethesda Purple Line platforms.
(the future CCT deck is shown overhead, at the upper right)
Source: Transitway Planning Update of 10/14/10 (pdf)

The MTA began to distribute the brochure Fast Facts about the Purple Line & the Capital Crescent Trail” which makes this unqualified statement:

The trail will continue through the Bethesda tunnel

The trail will continue through the existing Bethesda tunnel as well as having a surface route on Elm Street (which is to be constructed by Montgomery County).

There was a strong aspiration at the start, over 20 years ago, that the CCT would remain in the tunnel with the Purple Line. But it was not an expectation. We all knew there were many uncertainties. But that aspiration has evolved over time to became an expectation. MTA must take much of the responsibility for that – its presentations and materials should have continued to prominently reflect the uncertaintly associated with digging under the APEX building, until their measurements and analysis could more clearly show what was realistic.

We all can share the disappointment and frustration of learning so late that the cost and risk of keeping the trail in the tunnel is so high, regardless of whether we support or oppose the Purple Line. In hindsight, I think we all got caught up in wishful thinking. I do not believe there was any intent at MTA to mislead, but they have handled the expectations badly.

Now we must take a deep breath, calm down, and make some hard decisions.

No escaping a hard decision

Sunday, February 26th, 2012

(Another version has been cross posted at Greater Greater Washington.)

February 27 update: MTA has released its single-track operational analysis study and report to the County Council and other interested parties today. Unless experts can find major flaws in the study, I think we can put this issue to rest.

This blog has followed the evolving plans for the CCT and the Purple Line at the Bethesda Air-Rights Tunnel with numerous posts in the Bethesda Tunnel blog thread. Planners have been struggling with the rising cost estimates for keeping the CCT in the Bethesda Tunnel on an overhead structure above the Purple Line, and have requested the MTA look at alternative approaches including: 1) moving the Bethesda station platform east of the tunnel; 2) moving the platform to be under a new, redeveloped Air-Rights Building; and 3) using variations of platform locations that use reduced width track profile in the tunnel, i.e. single track or gauntlet track. The MTA has just submitted a draft of its study findings to the County Council, CCT Tech Report_20120224, and the Council T&E Committee is scheduled to take the issue up in a March 1, 2012 worksession.

The report findings are a disappointment to those of us who had hoped we could escape making a very hard decision. All of the new alternatives would seriously degrade the level of service and operational capabilities of the Purple Line or would have unreasonable cost.

I can quibble with some parts of the MTA draft report – for example MTA’s analysis of the three reduced transitway width alternatives :

…All three of the reduced transitway width alternatives yielded very similar performance results in operational simulations. None of the three will enable the Purple Line to operate at the six-minute headway required to carry the peak period passenger demand. With substantial portions of the Purple Line operating in street-running conditions subject to traffic interference especially at intersections, the train operations need to be able to have a schedule recovery time at terminal stations, including the Bethesda Station. The operational limitations imposed by these reduced transitway width concepts at the Bethesda Station would not allow for this recovery time, which would severely reduce the reliability of the service for the entire Purple Line. Therefore, due to these fatal operational deficiencies, this family of alternatives was eliminated from further study.

This analysis would apply to the CCCT single-track proposal as well. But the MTA draft report gives no information on the method and assumptions used for the operational simulations. While I may not be qualified to judge the technical merits of the simulation, there are interested parties in M-NCPPC, MCDOT, and in the trails community who can. I will feel more comfortable accepting the MTA conclusion if they make the operation simulation available for review. In fairness, this is an early draft report and perhaps the final report will show more. In any case I reluctantly think they are probably right on this. I can find no examples of successful single-track operations for a terminal station with a short headway requirement.

As much as I wish it were otherwise, we are back to the hard choice: either spend a now estimated $50.9M 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.

For me the right choice is to develop the alternative surface route to the fullest extent possible. $50.9M 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. As I observed at Taking a hard look at the tunnel I don’t think the switchback and cage on the tunnel route will be attractive to most of us, certainly not inviting enough to justify spending $50.9M. There is also too much risk that digging under the APEX building will destabilize the entire building. I’m still in shock at seeing our long transit center nightmare in Silver Spring because engineers underestimated the risk of a construction method. I don’t want another mess like that along the future CCT in Bethesda.

I think it is likely the Council will decide against accepting the cost and risk that comes with keeping the CCT in the Bethesda Tunnel. The political blowback from this decision will be intense, you can already see some of that in the comments to the Washington Post story Planners reject proposal…. “Save the Trail” advocate Pam Browning and others are advocating for a third option, i.e. 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 and the on-road trail route we continue to deal with east of Bethesda.

Bridges and tunnels

Friday, December 9th, 2011

Cross posted at Greater Greater Washington with edits.

The one thing I remembered from my high school Latin class is this phrase that I thought was from Caesar in one of his letters during his Gallic War Campaign:
“One of the tragedies of life is the murder of a beautiful theory by a brutal gang of facts.”
But now I learn that even that is wrong. It is most commonly attributed to either Benjamin Franklin, or to La Rochefoucauld, François duc de, 1613-1680.

That phrase comes to mind when I consider finding an alternate to the tunnel under the Air-Rights Building for a grade-separated crossing of Wisconsin Avenue for the Capital Crescent Trail. The “beautiful theory” part is the belief held by some 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 at Viers Mill Rd.

The Rock Creek Trail Bridge over Viers Mill Road
Source: National Transportation Enhancements Clearinghouse / www.enhancements.org

But the “brutal gang of facts” part is the array of constraints presented by the urban and crowded design space in Bethesda at Wisconsin Avenue.

Don’t block the driveway unless you are willing to buy the building.

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 and parking structure driveway entrances.

map of bridge over Wisconsin Ave.

Conceptual location of bridge and bridge ramps
over Wisconsin Avenue at Bethesda Avenue
(click on image for a larger image)

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 (16′ plus 2′ assumed). 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 major driveways on either side of Bethesda Avenue.


View Larger Map

This driveway on Bethesda Ave. must not be blocked by a trail ramp.

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 Ave. bridge crossing where long ramps would not create unacceptible blockages of driveways and business entrances, we will get the same result. Crossing at Elm Street, Miller Avenue or Leland Street will also 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 south of the rest plaza 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 the rest stop and 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 Plaze, 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. See Dan Reed’s alternative view of the CCT in Bethesda at On-street crescent trail may be better for bikes and peds.

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.

map of tunnel under Wisconsin Ave.

Conceptual location of tunnel and tunnel down ramps
at Bethesda Avenue and Willow Street.
(click on image for a larger image)

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: 1) the existing elevation change along Bethesda Avenue helps for a down ramp, instead of forcing us to “chase the grade” for an up ramp, and 2) 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 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 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 cost, 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 at CCT Update.

“…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 in part. I think there is little value in exploring an alternative grade-separated option much further. The “brutal gang of facts” 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 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.

Air Rights Building off the table

Friday, December 2nd, 2011

The CCCT and other stakeholders met with Councilmember Berliner on Dec. 1 to advocate for keeping the Trail in the Bethesda tunnel, reported at the CCT News and Events. The Planning Board sent its recommendations to the Council in a Nov. 30 letter. There have been some changes since the issues were reported in earlier blog posts here.

The Council T&E Committee is now expected to take the issue up in a January 30, 2012 meeting and not on Dec. 5. This is to give MTA enough time to evaluate the options and give the Council a report.

Tearing down the Air Rights Building is apparently no longer being considered. Discussions between Council and the Planning Board have “clarified” this to mean that they will evaluate building the Purple Line station under the parking structure at the east side of the Air Rights Building, where the tunnel is a little wider. This is clearly a change from the discussion at the Planning Board on Nov. 17, when the Commisioners were talking about tearing down the building itself.

The Bethesda tunnel at the east end

CCCT succeeded in getting Councilmember Berliner to request that a more substantive response to their single-track proposal be prepared by MTA. The Councilmember noted that MTA resistance to single-track is very strong and MTA will not likely yield on this issue, but a response that quantifies the impacts of single-track impacts on the transit operations is needed to put the issue to rest.

The Planning Board is recommending in its letter that $40M is an unacceptible price to pay to keep the Trail in the tunnel. The Town of Chevy Chase is already expressing concern that the options that would place the station platforms at the east end of the tunnel or at Pearl Street might be unacceptible to the Town because of the impacts of having platform operations adjacent to residences. I believe the MTA will report substantial reductions in predicted ridership and cost effectiveness of the Purple Line system if long walking distances are created for transit riders by moving the station platform east. I believe it is most likely a surface route for the Trail is the option that will survive the selection process at the County Council next month.

The Planning Board Nov. 30 letter recommends setting up a panel of agencies and the Town of Chevy Chase to evaluate design options for the Trail surface route, and lists design treatments that can be considered to make the route safer and more attractive. CCCT asked Councilmember Berliner to put the CCCT, WABA and other trail stakeholder groups on the panel. WABA and CCCT also advocated at the meeting with Councilmember Berliner that planners should give a trail bridge or tunnel serious consideration to avoid the at-grade Trail crossing at the Bethesda Avenue/Wisconsin Avenue intersection if the Trail is removed from the Bethesda tunnel.

The engineer in me is very doubtful that a successful trail bridge or tunnel across Wisconsin Avenue can fit into this area. The constraints imposed by the streets, existing major buildings, and elevation change from Woodmont Avenue to Wisconsin Avenue will force designs that are very unattractive to trail users, even if cost is no issue. But I’d be happy to be proven wrong on this – just show us the design concept that works. In the mean time, we should not buy into “Save the Trail” and other Purple Line opponents’ efforts to hype the danger of crossing Wisconsin Avenue to hysterical levels. Yes, any at-grade crossing of a busy highway should be avoided wherever an attractive trail bridge or underpass is possible for a regional trail like the CCT. But no, the trail network will not be destroyed if we must cross in a protected crosswalk at a well redesigned intersection.

Taking a hard look at the tunnel

Saturday, November 19th, 2011

A $40M price tag on keeping the trail in the Bethesda Tunnel should prompt us to take a hard look at what the $40M would buy. I’m taking a second look, and the trail that we would have in the tunnel over the Purple Line looks too much like damaged goods to pay such a premium price to save.

Last year I wrote about Bethesda tunnel west. Cyclists need to reconsider the narrow switchback ramp at the west end of the tunnel that will require dismounting. Is this what we want? Is it worth fighting hard for?

MTA concept for the CCT in the Bethesda tunnel
(click on the image for a large image)
Source: MTA Plan and Profile – Trail, September 2010

Dan Reed wrote a thought provoking post for Greater Greater Washington, On-street Crescent Trail may be better for bikes and peds. Among the comments to the post is my response to a comment from Jack Cochrane of CycleMoco:

@Jack:

I like the tunnel, and this may sound like sour grapes now that it is becoming ever more apparent keeping the trail in the tunnel is not practical, but -

The plan for rebuilding the trail to be overhead the Purple Line in the tunnel will not give us the direct connection you would like. If going east from Woodmont Avenue, cyclists would have to pass through the conflicts in a very pedestrian active Woodmont Plaza to get to the tunnel entrance. Then they would be required to dismount, and walk up a tortuous switchback ramp built into the back side of a new JBG building to get to the overhead. The trail in the overhead will be at least as wide as the trail is in the tunnel today, but will have a vertical clearance as little as 8′. This will make it feel much more confining than it does today.

The proposed surface route will be less than 400′ longer than the tunnel route. You will only need to stop riding if you have to wait for the light at Wisconsin Avenue. A 10-12′ wide shared use trail on the north side of Bethesda Avenue and a shared use trail or cycletracks on Willow can separate cyclists from traffic.

Quite frankly, if I were to cycle through Bethesda and have that choice, I’ll take the surface route rather than deal with the dismount and walk up the narrow switchback ramp into the tunnel at the west end. Pedestrians and families with small children on bikes might still prefer the tunnel route, but few adult cyclists will use it under those conditions. You know better than most how adverse cyclists are to dismount zones. The tunnel route is not worth $40M for cyclists.

Maybe I am suffering from a sour grapes syndrome now, but the tunnel route does not look so hot when we take our rose colored glasses off and look straight at that switchback ramp.

Planning Board to JBG – “Think again.”

Friday, November 18th, 2011

The Planning Board took up the Bethesda Tunnel issue at its Nov. 17 meeting and decided that all options should be considered to keep the trail in the tunnel. As reported in the Washington Post and WashCycle, the Planning Board asked that placing the Purple Line Bethesda Station on the east side of Wisconsin Avenue or taking down a building over the tunnel be evaluated.

The Planning Board heard the Coalition for the Capital Crescent Trail argue that single-track in the tunnel should also be considered, see the CCCT single-track position. MTA argued that single-track in the tunnel would make the Purple Line slow and too unreliable. the Planning Board accepted the MTA opinion and did not recommend the single-track for further evaluation. In my view, that was a mistake.

Source: CCCT single-track position

It may turn out that the MTA opinion that single-track will interfere with Purple Line operations too much is true. But MTA failed to present anything to substantiate that opinion at the hearing. MTA Project Manager Mike Madden attempted to point to an earlier single-track study as proof that single-track in the tunnel would not support the needed headways. That study was for a much longer section along the line between tunnels, stations, and one of Madden’s own engineers consulting engineer Harriet Levine admitted that study was not relevant for this case. MTA argued that they would have to make the north platform much larger if the south platform was removed, but did not explain why this is so. Under the current plan, all passengers getting off a train on the north track would exit to the north platform to go to the elevators and stairs on that side. No one would have any reason to exit a train to the south side, so the north side platform must be wide enough to handle all traffic regardless of whether a south side platform is present. And, in any case, there is room to expand the north side platform while still preserving a trail if the south side platform and track are removed. The MTA said they could not give up the ability to keep another train at Bethesda on the south track, but they did not explain why the tail track presented in the CCCT statement would not serve to do this. In short, the MTA staff were pulling ideas off the top of their heads.

If the Planning Board can ask the MTA to evaluate tearing down large buildings or moving the transit station hundreds of feet away from the connection to Metro, then the Planning Board can also ask MTA to substantiate their assertions that single-track will not work. If single-track can work, it would be by far the easiest and cheapest to build.

The Planning Board did send a very clear message that it will make the alternate trail surface route a priority, especially if the trail is removed from the tunnel. Representatives from JBG Associates gave testimony that a shared use trail along the north side of Bethesda Avenue would conflict with their plans, and therefore the trail should be bike lanes on Bethesda Avenue instead. JBG had earlier planned to build an office and retail building at the northeast corner of Woodmont and Bethesda Avenues, see the CCCT news report. But JBG now intends to come to the Planning Board soon with a request to instead build a large hotel there, with a hotel driveway entrance. The JBG representatives felt that a busy shared use trail would not be consistent with their proposed driveway.

Planning Board Chair Francoise Carrier agreed that a busy trail on the north side of Bethesda Avenue and a hotel driveway entrance would conflict, but she pointed out the trail has been in the Master Plans since the 1994 Bethesda Sector Plan.

Capital Crescent Trail Street Level Route
Source, 1994 Bethesda Sector Plan

The Planning Board Chair told the JBG representatives they should reconsider their plans and not bring a plan to the Board that is not compatible with the Master Plan. The signal was clear – if a hotel and the trail cannot both work here, a hotel will not be approved. If the Planning Board and County Council can show this priority consistently along the surface route, then it can become even better than the trail Dan Reed envisions at On street CCT may be better for bikes and peds

Learning to like the Bethesda surface route

Thursday, November 10th, 2011

The Montgomery County Planning Board is considering whether to recommend to the County Council that we go forward with keeping the CCT in the Bethesda Tunnel, now that the cost estimate has risen to approx. $40M, or to recommend using an alternative route along Bethesda streets instead. On November 3 the Board and staff took a tour of the tunnel to look at the options. On November 17 the Planning Board will have a worksession on this and other issues including lighting, landscaping, and connecting to the Rock Creek Trail. The Planning Board will hear staff recommendations and take public input. Information on how to give testimony is on the M-NCPPC website agenda page. Also now available on the website is the M-NCCPC staff report with the recommendations that will be presented to the Planning Board on November 17.

The staff recommendations come with a very good analysis of the cost and benefits of the tunnel route, and also a thorough analysis of the alternative surface routes. Regarding the tunnel route, the staff recommends:

It appears that more design work is needed before a recommendation can be made with confidence on whether to construct the Capital Crescent Trail in the tunnel.
a. Should further engineering investigation reveal a much lower cost or risk differential or should a mechanism present itself to provide the funds to reduce the public outlay and/or risk to the Apex Building, constructing the trail may yet be found to be feasible.
b. We recommend that MTA brief the County Council in six months time with updated cost estimates and risk comparisons so that this decision can be made with greater assurance.
c. If the cost differential remains, the County Council should determine the tunnel route to be financially infeasible and concentrate more effort on building the planned surface trail to accommodate the volume and variety of user groups.

There may be something uncovered in the tunnel structures during a six-month engineering investigation that will overturn the huge cost differential we are looking at now. But I doubt it. The CCCT is suggesting a short single-track Purple Line section could be used at the tunnel, to make it easy to keep the trail in the tunnel. But if that single-track concept is found to be not practical, then we are likely looking at a decision to reroute the CCT on Bethesda streets.

The M-NCPPC staff report gives a good description of three alternative routes, and recommends the route along Bethesda Avenue (the dashed yellow route below).

Alternate CCT surface routes in Bethesda
Source: M-NCCPC staff report

The Bethesda Avenue Route has long been proposed as an alternative route to be built in addition to the trail in the tunnel, for local trail access. The M-NCCPC staff recommend that, in the event this becomes THE route of the CCT, this route be developed much more extensively than has been planned. Their report lists specific recommendations for shared use off-road trail sections down Bethesda Avenue, Willow Street and 47th Street and to realign the Wisconsin Avenue crosswalk. But most impressive are the recommendations to change the traffic lights:

Intersection of Wisconsin Ave and Bethesda Ave: Crossing Wisconsin Ave is the greatest impediment to creating a viable surface alignment. Therefore, it is critical to prioritize pedestrians crossing Wisconsin Ave. We recommend eliminating the conflicts for pedestrians crossing Wisconsin Ave by either:
  • Prohibiting left turns from Bethesda Ave to northbound Wisconsin Ave and prohibiting right turns on red in the southbound direction to eliminate all conflicts between trail users and motor vehicles
  • Providing a pedestrian only phase.

Both of these modifications would likely require signal retiming along Wisconsin Ave.

If all of these changes were in place, then I would find this route to be almost as good as the route through the tunnel. This surface route is about 400′ longer than the tunnel route and has a wait for a signal at Wisconsin Avenue. But it would be in the open and partially in a local park rather than being in a long tunnel. IF the signals at Wisconsin Avenue can be changed to eliminate the interferences with motor vehicle turning traffic, then crossing Wisconsin Avenue would be safer than is crossing Bethesda Avenue and Woodmont Avenue at the CCT Bethesda Trailhead today.

The tunnel route remains the most direct and safest CCT route. We may find a way to save it if the cost differential changes on further study, or if we find that single-track can work at the Bethesda Purple Line station. But losing the tunnel route is not an existential threat to the future CCT. I can learn to like the alternative Bethesda Avenue route if it is done right.