Why Going Underground Makes Sense in Tysons Corner

Of course, TysonsTunnel.org and its team have already made comparisons. They say it's all good news for the tunnel.

The total cost of the tunnel, at slightly more than $800 million, appears to be below the probable total cost of the elevated line. Moreover, the team predicts that the tunnel cost could be even less once the design is finalized and value engineering is completed. In addition, the tunnel option's life-cycle costs will be lower, a savings of about $5 million per year. And a tunnel's lifespan is potentially twice that of an aerial structure.

The team says the tunnel could be constructed about six months more quickly than the aerial structure, noting that tunneling avoids the need to move utilities or reconstruct roads.

Entailing almost totally underground construction, the tunnel option would be cleaner and much less disruptive of life above ground. Building an elevated line would require major road reconfiguration and bring years of severe traffic congestion exacerbated by construction trucks continually rolling through the heart of Tysons, along with construction noise and increased air pollution.

By contrast, with tunneling, dump trucks carrying excavated material will exit only at the ends of the tunnel on highway medians outside Tysons Corner.

But immediate and long-term aesthetic benefits still constitute one of the best arguments in favor of the tunnel and against an elevated line. Visualize a parade of tall, structural supports soaring over and slicing through the heart of Tysons. Leesburg Pike would never become a walkable boulevard.

Ponder the history of elevated, urban rail lines, most now demolished, that produced unwanted dirt, noise and vibration, became visual and physical barriers and compromised the value of abutting land.

Why build something that we will want to tear down a few decades from now?

Gov. Kaine can find political comfort in one other piece of knowledge. For all the reasons cited by tunnel advocates, Northern Virginia voters overwhelmingly favor the tunnel option, as does an independent panel of professional engineers.

And let's not forget Metro, which, strange as it seems, has little say in choosing between options, yet must ultimately operate and maintain the line. Metro officials prefer the tunnel.

For the governor, putting the tunnel back into play is not only a wise decision, it's an easy call.

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