sentences:  The highway serves Washington, D.C., via I-270, which was once designated Interstate 70S.Uniquely, I-70 indirectly serves a branch of the Washington Metro at Shady Grove via I-370, which only connects to I-270.I-70 was planned to end at I-95 in Baltimore, but due to local opposition, it was only built to Maryland Route 122 (MD 122).