Going Over, Under and Around and Around on the Dulles Metro Expansion

Concerning the proposed 23-mile Metrorail Orange Line extension to Dulles International Airport and whether the Tysons Corner portion of the line should be elevated or run through a tunnel, I offer this advice: Just as it's often a good idea to question authority, it's also appropriate to question design strategies, construction cost estimates and short-sighted budgets.

The Washington Post reported last week that the contractors responsible for managing the rail extension project "found that the tunnel approach would cost at least $500 million more than the above-ground plan."

The project managers, consultants to the state of Virginia who have received millions of dollars in fees for preliminary design and engineering, assert that the cost difference for tunneling would be even greater if proposed cuts in the current, elevated railway design are accepted. These cuts would eliminate pedestrian bridges over busy roads, remove some escalators at the four Tysons stations and reduce the number of rail cars running on the line.

In other words, in the interest of meeting a constrained budget, the project managers not only are rejecting the tunnel option but also are subtracting desirable amenities from the above-ground option.

According to Post staff writer Alec MacGillis's report last week, Virginia Transportation Secretary Pierce R. Homer summarized the current, cost-driven philosophy: "We have to balance out the issue of cost and amenities and deliver the core function -- we pledged to hold costs down as much as possible, and that's our first responsibility."

But, in the long run, should that be the first responsibility?

Tunnel advocates -- Metro officials, Fairfax County political leaders, Tysons property owners, local residents -- are concerned about the project philosophy and the project managers' conclusions.

They understand that building an elevated rail line traversing Tysons Corner, while accomplishing transit objectives, would fail to achieve other important goals. They believe the tunnel option greatly enhances the desired transformation and, in fact, may prove to be more economically effective if all costs and benefits are accounted for.

An elevated rail line slicing through Tysons Corner is a bad idea. It would be visually intrusive and obstructive. Generating noise and vibration, it would compromise the quality and value of abutting real estate. And exposed both to weather and to dynamic stresses, the elevated structure, no matter how well engineered, would require continual maintenance.

Further, the lengthy process of constructing an elevated rail line through Tysons will be extremely disruptive. In addition to producing noise, vibration, dust and traffic tie-ups for several years, it will require relocating utilities and rebuilding parts of roads.

Building tunnels is less problematic and more environmentally friendly. A tunnel can be more flexibly aligned and shorter. Unaffected by weather, tunneling can proceed around the clock, the only sign of activity being periodic comings and goings of trucks required to transport excavated material.

Experts in state-of-the-art tunnel design and construction technology are also skeptical about the project managers' numbers. They assert that large-bore tunneling, accomplished by giant boring machines developed and used extensively in Europe, is economically competitive. These machines, which look like something out of a "Star Wars" movie, can drill through the Earth at the rate of 50 to 100 feet per day and, as they progress, expel excavated material while installing prefabricated, reinforced concrete tunnel liners.

Moreover, the diameter of a tunnel can be large enough to accommodate not only station platforms and necessary vertical access, but also four tracks, two over two. That would allow Metro to use the tunnel for express trains or to store out-of-service rail cars.

This week, Virginia officials and the Metropolitan Washington Airports Authority made a deal whereby the airports authority will take over responsibility for financing and building the rail extension. But the authority's responsibility transcends just getting a rail line built.

Instead, the authority must consider the interests of everyone, now and for decades to come, affected by the Orange Line extension: Dulles Airport employees and travelers from around the world; citizens of Fairfax and Loudoun counties; and future Tysons Corner residents, workers and property owners.

Designed properly, transit to Dulles will catalyze redevelopment of Tysons Corner, still the poster child for poorly planned, dysfunctional edge cities. A denser, mixed-use, pedestrian-friendly Tysons Corner, already encompassing an area larger than many American downtowns, has the potential to become an extraordinary, model urban community.

Thus, the airports authority has both an opportunity and an obligation to fully evaluate the tunnel and elevated railway options.

It should immediately retain independent, technically and economically qualified consultants to assess and compare costs and benefits. Such an assessment would consider direct construction costs as well as life-cycle expenses for operation and maintenance. Equally important, it would consider positive and negative impacts on streetscapes, adjacent properties and property values, property tax revenue, and environmental quality.

History also should be heeded. In recent decades, governments have expended billions of dollars to demolish elevated highways and rail lines that seemed like good ideas at the time but turned out to be eyesores and urban barriers.

What folly it would be to design and construct an elevated rail line through Tysons Corner in light of such history.

Finally, the airports authority should seriously review the budget for the Orange Line extension. Given that it will be creating infrastructure to last for generations, and infrastructure with profound land-use impact, it should question whether today's budget and financing strategy are realistic. It should wonder why project managers are already removing desirable elements of a system whose design is not yet complete.

Why pursue compromise and mediocrity from the outset, something Metro happily resisted during its creation?

Even if an elevated rail line structure initially costs less to construct than a tunnel, which remains in question, a tunnel is still the right way for Metro to go through Tysons Corner.

Roger K. Lewis is a practicing architect and a professor of architecture at the University of Maryland.