High Quality Content by WIKIPEDIA articles! Interstate 270 (abbreviated I-270) is a 34.70-mile (55.84 km) auxiliary Interstate Highway in the U.S. state of Maryland that travels between Interstate 495 (the Capital Beltway) just north of Bethesda, Montgomery County and Interstate 70 in the city of Frederick in Frederick County. It consists of the 32.60-mile (52.46 km) mainline as well as a 2.10-mile (3.38 km) spur that provides access to and from southbound I-495. I-270 is known as the Dwight D. Eisenhower Memorial Highway as well as the Washington National Pike. 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.