Maryland Route 100 is a major east–west highway connecting U.S. Route 29 in Ellicott City and MD 177 in Pasadena. MD 100 also connects to Interstate 95 (I-95), US 1, the Baltimore–Washington Parkway, and I-97. The highway connects Howard County to the west with Anne Arundel County and the Chesapeake Bay to the east. MD 100 also provides access to the Baltimore–Washington International Airport (BWI) and the Arundel Mills shopping mall.

U.S. Route 29 (US 29) is a north–south United States Numbered Highway that runs for 1,043.3 miles (1,679.0 km) from Pensacola, Florida, to the western suburbs of Baltimore, Maryland. In the U.S. state of Maryland, US 29 is a major highway that emerges from Washington DC and runs north into eastern Montgomery County, stretching over 25.86 miles (41.62 km) through the state and terminating at Maryland Route 99 (MD 99) outside of Ellicott City. It serves the cities of Columbia and Ellicott City and provides the westernmost north–south route between Washington DC and Baltimore.