The tunnel under the Capitol Reflecting Pool was part of the Center Leg that was actually finished in the 1970s.
Southwest Freeway (I-395) was built as part of this project.
Parts of the Inner Loop would be completed, but the idea of a 2nd beltway would eventually be abandoned in the 1970s. The Southwest Freeway and the I-395 tunnel under the Capitol Building remain today as evidence of how the system would have functioned. The D.C. Metro would eventually navigate parts of the proposed route, although this followed a different pattern of planning. In the midst of this highway debate from the 1950s-1970s, Washington would experience significant change. At the top of this list is the concept of Home Rule, where D.C. became more able to locally govern itself as of 1973. The District Department of Transportation (DDOT) now maintains the highway system in Washington, D.C.
Southwest Freeway where it connects to the 14th Street Bridges