Interstate 635 (I-635) is a 37-mile-long (60 km) partial loop around Dallas, Texas, in the United States between I-20 in Balch Springs and State Highway 121 (SH 121) at the north entrance of the Dallas/Fort Worth International Airport (DFW Airport) in Grapevine. It intersects I-35E at exits 27B and 27C, but does not connect with I-35W. A small part of I-635 and I-20 is collectively designated as the Lyndon B. Johnson Freeway; known locally as the LBJ Freeway, or simply LBJ. The roadway is named after Lyndon B. Johnson, the former US Senator from Texas, 37th Vice President, and the 36th President of the United States. Where I-635 ends at I-20, I-20 continues the LBJ Freeway designation heading west. Since the portion of I-20 between State Highway Spur 408 (Spur 408) to I-635 retains the sam