I-70's route from Frederick to West Friendship was constructed as a divided highway relocation of US 40 in the early to mid-1950s and a freeway bypass of Frederick in the late 1950s. The first section of the Interstate to be marked as I-70 was an upgrade of US 40 near Hancock in the early 1960s. The remainder of the Interstate highway in Maryland west of Frederick was built on a new alignment in the mid- to late 1960s. I-70 was constructed from West Friendship to its present terminus in Baltimore in the late 1960s. The highway from Bartonsville in Frederick County to West Friendship was upgraded to Interstate standards in the mid-1970s. The final non-limited access portion of I-70 between Frederick and Bartonsville was eliminated in the mid-1980s. The Interstate has been upgraded through Frederick in a series of projects that began in the late 1990s.
