Interstate 270 (abbreviated
I-270) is a
auxiliary Interstate Highway in the
U.S. state of
Maryland that travels between
I-495 (the Capital Beltway) just north of
Bethesda,
Montgomery County and
I-70 in the city of
Frederick in
Frederick County. It consists of the mainline as well as a spur that provides access to and from southbound I-495. I-270 is known as the
Washington National Pike, and makes up the easternmost stretch of the
Dwight D. Eisenhower Memorial Highway. Most of the southern part of the route in Montgomery County passes through suburban areas around
Rockville and
Gaithersburg that are home to many
biotech firms. This portion of I-270 is up to twelve lanes wide and consists of a
local-express lane configuration as well as
high-occupancy vehicle lanes that are in operation during peak travel times. North of the Gaithersburg area, the road continues through the northern part of Montgomery County, passing
Germantown and
Clarksburg as a six- to eight-lane highway with a HOV lane in the northbound direction only. North of here, I-270 continues through rural areas into Frederick County and toward the city of Frederick as a four-lane freeway.