Virginia State Route 110

Virginia State Route 110 (SR 110) is a primary state highway in the U.S. state of Virginia. Known as the Jefferson Davis Highway, the state highway runs 2.41 miles (3.88 km) from U.S. Route 1 (US&nbsp1) and Interstate 395 (I-395) in Crystal City north to I-66 in Rosslyn within Arlington County. SR 110 is a four- to six-lane freeway that parallels the Potomac River, providing a connection between several of Arlington's urban villages. The state highway also provides access to the Pentagon, which is the headquarters of the United States Department of Defense, the grounds of Arlington National Cemetery, and SR 27, an east–west freeway between the Pentagon and the cemetery. SR 110 is a part of the National Highway System for its entire length.

SR 110 is a part of the Pentagon road network, a network of freeways and surface roads built concurrent with the construction of the Pentagon in the early 1940s. The state highway received its numerical designation in 1964 when maintenance responsibility was transferred to the Virginia Department of Transportation. SR 110's most significant changes in routing were relocation of the highway in Rosslyn to tie into I-66 in the 1980s and relocation of the freeway at the Pentagon to provide a larger security buffer for the building after the September 11 attacks. The highway is sometimes closed for large events held at or around the Pentagon, including the Marine Corps Marathon.