md 170 originally served as the main highway between baltimore and fort george g. meade. this highway, which included part of modern md 174 west of severn, was mostly constructed shortly after camp meade was established during world war i in the late 1910s. the odenton–severn portion of md 170 was originally built as md 554 in the 1930s, but became part of md 170 in the mid-1940s. md 170 went through another round of upgrades in the early 1940s due to its strategic importance during world war ii. the highway originally passed through the area now occupied by bwi airport. md 170 was relocated north of md 176 in the late 1940s during the construction of the airport and south of md 176 in the late 1950s. the highway has been expanded to four lanes around its interchanges with i-195, i-695, md 32, and md 100 and along the perimeter of bwi airport since the 1960s.