page_title: Interstate 270 (Maryland)
section_title: Route description
hierarchical_section_title: Interstate 270 (Maryland) / Route description
caption_attribution_description: Northbound I-270 north of Baker Valley Road, Rockville, Maryland
context_page_description: Interstate 270 is a 34.70-mile auxiliary Interstate Highway in the U.S. state of Maryland that travels between I-495 just north of Bethesda in Montgomery County and I-70 in the city of Frederick in Frederick County. It consists of the 32.60-mile mainline as well as a 2.10-mile 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 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 an 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.
context_section_description: I-270 heads northwest from an interchange with I-495 (Capital Beltway) and MD 355 (Rockville Pike) in suburban Bethesda, Montgomery County as a six-lane freeway. The left lane on each side is used as a high-occupancy vehicle lane (HOV lane) for carpools with 2 or more persons in the northbound direction between 3:30 and 6:30 p.m. weekdays and in the southbound direction between 6:00 and 9:00 a.m. weekdays. At the southern terminus, I-270 only has access to and from the eastbound direction of I-495.  The road turns west and comes to an interchange with MD 187 (Old Georgetown Road) and Rockledge Drive (unsigned MD 187B). From there, I-270 continues west as a ten-lane freeway and merges with I-270 Spur, which provides access to and from southbound I-495. Past this interchange, I-270 continues north as a twelve-lane freeway with an HOV lane and five travel lanes in each direction. The route passes through wooded suburban areas, where prior to the cloverleaf interchange with Montrose Road (unsigned MD 927), I-270 takes on a local-express lane configuration with the outer two lanes serving as local lanes and the inner three lanes and the HOV lane serving as express lanes. Past Montrose Road, I-270 continues north into the Rockville area, turning northwest before it comes to a single-point urban interchange with MD 189 (Falls Road), where the highway sees 253,620 vehicles daily.  The road continues to a modified cloverleaf interchange with MD 28 (Montgomery Avenue). Past MD 28, the freeway passes numerous business parks and some wooded areas before coming to an interchange with Shady Grove Road.
  Past this interchange, I-270 leaves Rockville and heads into Gaithersburg, where it intersects I-370. This highway provides access to a park and ride lot at the Shady Grove station, which serves Washington Metro's Red Line, and MD 200 (Intercounty Connector), which heads east to I-95 in Laurel. Past I-370, the local lane configuration ends in the southbound direction, which now has an HOV lane and four travel lanes while the northbound direction still has an HOV lane, three express lanes, and two local lanes.  I-270 continues past more suburban development before coming to a northbound exit and southbound entrance with MD 117 (West Diamond Avenue). Past this interchange, the southbound HOV restrictions end and I-270 continues north with four travel lanes in the southbound direction and an HOV lane, three express lanes and two local lanes in the northbound direction before reaching MD 124 (Quince Orchard Road).  Past MD 124, the local lanes in the northbound direction ends, and I-270 head northwest as an eight-lane freeway with four southbound lanes and an HOV lane and three travel lanes northbound, reaching a diamond interchange with Watkins Mill Road. It passes through wooded areas, leaving Gaithersburg, and comes to an interchange with Middlebrook Road.  The freeway narrows to six lanes again past at this interchange, with three lanes in each direction including a northbound HOV lane. I-270 continues into the Germantown area and interchanges with MD 118 (Germantown Road). A short distance later, after passing by some business parks, I-270 comes to an interchange with MD 27 (Ridge Road) and Father Hurley Boulevard. Past MD 27, I-270 heads into more rural areas of woods with some farm fields, paralleled by a set of power lines. The road has an interchange with MD 121 (Clarksburg Road) in Clarksburg near the Clarksburg Premium Outlets and the northbound HOV restriction ends past this interchange, with I-270 continuing north as a four-lane freeway. The power lines stop paralleling the route and it continues through more rural areas of woods and farms, running closely parallel to MD 355. The median widens, with trees in the middle, and I-270 has weigh stations on both sides. The highway reaches Hyattstown, where it has an interchange with MD 109 (Old Hundred Road).
  A short distance past the MD 109 interchange, I-270 crosses into Frederick County, continuing northwest through rural woodland and farmland. It reaches the Urbana area, where th
caption: I-270 northbound approaching Frederick
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