Washington's Car Tunnels

By Elliot Carter | JULY 5, 2018


Automobile tunneling in Washington started off slowly enough in the 1940’s, beneath some of the city’s worst traffic choke points: the northwestern traffic circles created a century and a half before by urban planner Pierre L’Enfant.

[Click on the Image Above to Launch the Car Tunnel Story Map]

Despite their short length, the underpasses at Scott and Thomas Circles attracted existential levels of criticism. The Washington Post called it “one of the most spectacular civic controversies Washington has [ever] known.” The subsequent construction of the Dupont Circle underpass, and its related trolley tunnels was so epically disruptive that it’s a marvel any future tunnels were built at all. Conservative bodies including the National Capital Park and Planning Commission and the Mid-City Citizens Association opposed tunnelization, arguing that “with ‘mutilation’ of one circle, none of the others would be safe, and that Washington’s distinctive beauty would disappear.” President Franklin Roosevelt backed the plan, personally lobbying the District Commissioners to begin work, and thus the work began.

How did traffic engineers decide specifically which radial streets to underpass at each circle? Figures showed that the greatest number of trips came in and out of the city from the north and northwest, which shaped the through streets chosen for underpasses. Other than that, it was just a gut decision. "All we can do now is wait 10 years and see if we were right," D.C. Engineer of Streets S.R. Harrison told reporters in 1949, after selecting Connecticut Avenue for an underpass at Dupont Circle, instead of Massachusetts Avenue.

The fourth traffic tunnel of the 1940’s was certainly the odd child of the lot, a futuristic three lane tunnel passing directly through one side of the new Pentagon Building. Without the public accountability of their civilian highway counterparts, the Army Corps of Engineers was free to tackle their unique traffic challenges with daringly creative solutions. The new five sided military headquarters was so shockingly vast (the largest office building in the world, then and now) that its architectural design began to drift into the category of urban planning. Any building with a workforce of 30,000 and six zip codes surely needed its own highways, all the better internal ones. When the Pentagon opened in September, 1941 it tunnels could accommodate 25,000 arrivals per hour. The only unanticipated consequence was the near suffocating haze of exhaust fumes, a problem only rectified with the installation of massive ceiling fans.

Following the end of World War II, Washington’s traffic tunnelers sat idle for a decade, before springing into action towards the end of the Eisenhower Administration on the some of the largest transit projects the city has ever seen. Federal Interstate dollars flowed out into a sprawling river of asphalt along the area south of the National Mall. Southwestern residential neighborhoods already suffering from blighted conditions were literally walled off from the rest of the city, and development in the area is only now recovering half a century later. The wealthy Foggy Bottom neighborhood received similar perimeter wall treatment, but also got a short expressway tunnel allowing pedestrians to walk to the Watergate Complex and soon to open Kennedy Center.

To a modern eye, the mid-century highway tunnels don’t look great. The utilitarian passages are dominated by soot resistant ceramic tiling, low ceilings, and antiseptic overhead lighting. It didn’t have to be that way.

In 1963 a beautiful new tunnel opened in Rock Creek Park, passing through a hill, and directly beneath National Zoo administrative offices. The modestly scaled design employed just two lanes of traffic, but included generous 50-foot arching ceilings that showed there was an alternative to the prevailing flat-top designs. Driving through the Rock Creek Park tunnel is a pleasant countryside experience, in contrast to some of the busier underground highways that can sometimes feel like your making an end run on a Death Star thermal exhaust port.

Washington approached peak Death-Star in 1973 with  the completion of the first segment of the Center Leg Freeway. A half mile long dystopian tube dipping below ground near the Rayburn House Office Building and emerging north of the Department of Labor headquarters that was then nearing completion. The Center Leg experience is notable in its length, its ambient sounds (thunderous, and echoing), and its way-finding confusion for first time drivers.

Depleted city coffers and heightened inflation rates delayed the second  segment of the Center Leg Freeway for another eight years. In 1986 the final segment opened to the driving public, half in tunnel, and half in an unfortunate sunken trench.

Washington’s most recent bit of automobile tunneling is an effort to fix some of the damage wrought by the Center Leg. In 2010 the D.C. City Council passed legislation and awarded contracts to build a concrete deck over the four block long sunken highway trench north of Capitol Hill. The future space will accommodate five high rise buildings, a pedestrian plaza, and offers a much improved use of the surface streetscape.

Three dimensional computer mockup of the Center Leg Freeway redevelopment plan. Image:   Capitol Crossing  /Press Release

Three dimensional computer mockup of the Center Leg Freeway redevelopment plan. Image: Capitol Crossing/Press Release

As much as highway development over the past half century has eased commutes and helped suburban development flourish, their impact in central Washington has frequently isolated neighborhoods and created unpleasant swaths of high speed race track asphalt. Automobile tunnels, controversial, disruptive, and often ugly, carry water for the surface population by separating off high speed automobiles from city streets.




"Underpass At Thomas Circle Ready: $530,000 Feat Of Engineering To Be Previewed Tuesday, Wednesday," Washington Post, March 10, 1940

"New Scott Circle Underpass Open to Traffic," Washington Post, December 30, 1941

"Ol' No. 1550 Nonchalantly Makes First Run in Newly Opened Tube Under Dupont Circle," Washington Post, November 3, 1949

"New Rock Creek Parkway Link to Include Tunnel Through Zoo," Washington Post, April 15, 1960

"Bridge, Expressway Will Open July 31," Washington Post, July 22, 1962

"Washington Circle Tunnel is Activated," Washington Post, December 1, 1962 

"Expressway Due to Open Monday," Washington Post, July 10, 1965

"Barney Circle Gone, But Will Return," Washington Post, June 19, 1971

"Televised Tunnel Opened Under Mall," Washington Post, December 21, 1971

"Sophisticated District Freeway to Open Soon," Washington Post, October 14, 1973

"After 8-Year Wait, Last Segment of Center Leg Freeway Nears Completion," Washington Post, December 10, 1980

"I-66: The Computer is King of the Road," Washington Post, January 8, 1981

"Redevelopment of Center Leg Freeway (Interstate 395) Act of 2010," Council of the District of Columbia, October 26, 2010

"$1.3 Billion Capitol Crossing Project Will Be One of D.C.'s Biggest Projects Ever -- But Drivers, Beware," NBC News, June 13, 2015

"Third Street Tunnel Overview," District Department of Transportation

"An Administrative History - The Park and the Automobile," National Park Service

Top Image: Google Street View/Fair Use