What is VDOT Doing at Dunn Loring?

Transform 66 Wisely In-Depth Report

VDOT and their private contractor currently plan to build a massive bridge over the Dunn Loring area, including the entire Metro station and Gallows Road.  We named this designed bridge as the McAuliffe Bridge in honor of the Governor who has been pushing for the I-66 widening.  Why would VDOT & Co. propose a design so awful to the community?

The answer is more than just VDOT’s preference of concrete over communities.  A critical piece of infrastructure for the Metro rail system is in the way of their road widening plans.  This is the Traction Power Substation (TPS), located at the Dunn Loring/Merrifield transit station, between the new bus bays and the shoulder of I-66.


VDOT & Co. could move the TPS out of the way, but this is complicated.  For a road construction consortium, it is far easier (even if more expensive) to build a massive bridge structure than deal with complicated infrastructure owned by someone else (in this case, WMATA, the operator of Metro).

So what is a TPS?  It contains equipment that provides proper electrical power to make Metro trains run.  Each train car has traction motors that together make the train move.  Each TPS powers the third rail with 750 volt DC electricity, which is then received by the train cars.

While 750 volts is quite high compared to household use, it is not high enough to avoid significant power loss over distance.  For this reason, many substations are needed to power each Metro line.  While we won’t get into a complicated electricity discussion here, the short version is that electrical conductors lose power over distance (resistance), and higher voltages lose less power.  750 volts is a compromise between several factors, such as arcing and safety, and how far apart substations are needed to power a rush hour train schedule.  The TPS is supplied by many thousands of volts (higher voltage is transmitted more efficiently) from the electric utility.

To operate the Metro, WMATA guidelines call for a TPS about every mile.  This ensures that each train will have plenty of power at the proper voltage throughout the line.  The third rail is separated into sections, so power can be turned off in a section for maintenance or in case of an emergency without disrupting the entire line.  To control power in these situations, WMATA places breaker stations halfway between each TPS.


So, can VDOT & Co move the power substation?  With WMATA’s permission, sure.  But where would they move it to?  The answer lies with how far away the nearest TPS are in each direction.

To the west from Dunn Loring, the next power substation is at Cedar Lane, which is a mile down the tracks.  To the east, it is off of Barbour Road.  That’s almost 1.75 miles away from Dunn Loring, which is already stretching the WMATA specification.  So, if they move any further to the west, there is a problem.

VDOT & Co. recently suggested they could move the Dunn Loring power substation west to 2700 Prosperity Avenue, where there is space in the plans as this road curves away from I-66.

But moving the Dunn Loring TPS west to here would increase the distance between substations (Prosperity Avenue to Barbour Road) to nearly 2.25 miles.  This is a very long distance for Metro rail power. WMATA would like more power, not less, so they can run more eight car trains in the future.  They likely won’t allow a gap that long.

In addition, there is already a breaker station at 2700 Prosperity Avenue, making things more complicated.  A new breaker station would likely be required somewhere else, so another location would still be needed.
VDOT & Co. likely can’t move the substation to the west, and to the east is the Beltway interchange.  The Dunn Loring station has just been redeveloped as part of the public-private partnership there that includes shopping, apartments, and restaurants.  There isn’t much station land left that is out of reach of the widening shovels.  That gives VDOT & Co. two options: put the substation underground, or move it across Interstate 66.  Placing it underground near the station entrance would mean a major excavation that would be disruptive to everyone, and be even more expensive.

They can’t move it directly across I-66 without taking still more land away from the embattled schoolyard at Stenwood Elementary, already in the sights of VDOT & Co.’s bulldozers and cement trucks.  The likely choice would be to move the Dunn Loring power substation to Stenhouse Place instead of Prosperity Ave. VDOT already plans to demolish this established transit friendly neighborhood, so they could find enough land here.  But now they have another problem–getting the high voltage power feeds across the highway to serve the TPS, which is non-trivial and right in the middle of a complex area for them.

Substation relocation will require a lot of time consuming construction, coordination, and testing with WMATA.   Either way, this is a big project risk.   It isn’t insurmountable, but is a big mess for their contingency plans.  WMATA doesn’t sound very happy either.

Now VDOT & Co. has proposed a massive bridge over Dunn Loring so they don’t have to worry about the TPS relocation and its project impacts.  But VDOT “forgot” about this bridge and the TPS during all of the project public information meetings, the Commonwealth Transportation Board public meetings, the environmental impact/NEPA public hearings, and the each of the community briefings.  VDOT has boasted of “over 100 meetings” on the project, yet none of those meetings contained any reference to building an Interstate highway over Dunn Loring station, and Gallows Road.  One might question what is the point of having 100 meetings, or even one meeting, when crucial design components are changed later or left out completely.

Is the TPS impact a new surprise to VDOT?  The TPS at Dunn Loring has existed since this section of the Orange line opened in 1986.  It was hardly hidden or difficult to find before the previous meetings. Anyone walking from the bus bay or parking garage to the Dunn Loring metro entrance walks by it, although it is certainly possible that nobody at VDOT and Co. is familiar with a daily commute on a transit system.

But the TPS is easily viewed from aerial photography and VDOT has commissioned numerous detailed land surveys of the I-66 corridor in the past few years alone.  A quick conversation between VDOT and WMATA would also communicate the issue, which was also brought up by numerous members of the public at VDOT I-66 meetings in 2015.  In short, capable engineers working on the I-66 widening project for years should certainly be aware of it and coordinating with WMATA, whose tracks run right through the I-66 project.

When reporter Adam Tuss, of NBC Washington (channel 4), investigated, he discovered the opposite.  Here is what WMATA told Mr. Tuss on April 5, 2017:

Yesterday, VDOT notified Metro that, due to a proposed design change, the traction power substation at Dunn Loring would need to be relocated.  (This was the first notice to Metro of the proposed change.)  Under the agreement, there would be no impact to Metro’s operations and VDOT would incur the cost of any relocation.  The final approved design (including any infrastructure changes) will be determined by VDOT and any additional questions should be referred to them.

The detailed plans that contain the McAuliffe Bridge are dated October 2016, six months ago.  Once the McAuliffe Bridge plans were quietly made available this spring, members of the public were outraged that this scenario was even proposed.  When this outcry eventually reached VDOT & Co., they suddenly decided to look at alternatives to transforming Dunn Loring under a massive shadow.  A hastily written paragraph on VDOT’s website suggested that they had now begun a search for alternatives.  But why was this not done sooner?  VDOT has hired at least four “Communications” firms with millions of your taxpayer dollars in recent years for I-66 widening.

Yet, WMATA indicates that nobody initiated any communications with them regarding the TPS before releasing the McAuliffe Bridge plans.  This is not a good sign for things to come.  Imagine VDOT’s default communications style in a few years when VDOT & Co’s jackhammers, beeping trucks, pile drivers, and heavy equipment is operating 24 hours a day…

As mentioned earlier, VDOT & Co. would rather build a bridge than move Metro’s power system because they can control it.  Building a bridge is expensive, but their project managers can plan, budget, and schedule it, with most of the constraints well known and under their control.

Conversely, dealing with WMATA is a complete wildcard for VDOT & Co.  The scheduling and risks are not known, a project manager’s nightmare.  Metro’s power infrastructure requires special handling and many risks lurk behind any project affecting it.  The project must be carefully choreographed with railroad operations, the right parts and resources must be available on schedule, and WMATA would ultimately be in charge.

Any issues or surprises that arise will threaten the schedule of the larger I-66 project, and WMATA engineering is already preoccupied with its own infrastructure issues.  But a key reason for VDOT & Co. choosing the McAuliffe Bridge as their first alternative is spelled out in the executed I-66 Comprehensive Agreement between VDOT and its Developer, I-66 Express Mobility Partners:

The Developer  will  exercise  best  efforts  to  coordinate  with  WMATA  to  minimize  impacts  on  WMATA’s  operations  and  facilities.    All contractors working on WMATA Work must be prequalified and licensed as required by WMATA. 

The Developer will be responsible  for,  and  will  bear  the  costs  and  schedule  risk  related  to,  coordination  with  WMATA  regarding  the  WMATA Work,  the  WMATA  Easement  Impacts  and  the  WMATA  Incidental  Impacts.    Such coordination shall include  (a)  notifying  WMATA  before  performing  any  construction,  maintenance  or  repair  activities  which  could  affect  WMATA  transit  operations,  and  (b)  abiding   by   WMATA’s   reasonable   regulations   to   assure   the   safety   of   WMATA’s passengers  and  equipment  and  maintenance  of  WMATA’s  operating  schedules.    To the extent  WMATA,  pursuant  to  the  1991  Easement,  makes  a  successful  claim  against  [VDOT] for  Losses  arising  from  Developer’s  impacts,  the  Developer  will  reimburse [VDOT] for the amounts paid to WMATA….

So VDOT & Co. are on the hook for “minimizing impacts on WMATA’s operations and facilities.”  That’s a tall order for doing power infrastructure work.  And the costs of doing the work, plus the scheduling risks are put on VDOT’s contractor.  These unknown schedule and risk constraints are a challenge for any project manager.  Orange Line commuters will not and should not tolerate a rapid transit line shutdown for VDOT’s convenience.

We should also note that WMATA has a long term desire to upgrade its traction power infrastructure.  This is needed to operate more eight car trains.  If the TPS is moved, it could be upgraded with additional capacity at the same time.  With a little coordination and communication, VDOT’s and WMATA’s needs could align.  This would be an ideal solution to this problem.

VDOT’s contractor will have a 50+ year concession on I-66 tolls, and they should not be allowed to cover up Metro’s new transit village with a towering Interstate bridge for their convenience.

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