Interstate 270 travels 32.60 miles overall as a busy commuter route from Interstate 495 northwest to Interstate 70 and U.S. 40 at Frederick. The freeway sees a local/express roadway configuration from Exit 11 south to the split with I-270 Spur.

Interstate 270 Maryland Highway Guides

Oldest portions of Interstate 270 date back to the 1950s-expressway of U.S. 240 through Frederick County. The route became a part of Interstate 70S in 1956. U.S. 240 shifted from its surface route, which was redesignated Maryland 355, to a freeway southward from Frederick to the Capital Beltway near Chevy Chase. The US route overlapped with I-70S through to its decommissioning in 1972.1

Interstate 270 initially consisted of just the freeway spur to I-495 west from I-70S south in Montgomery County. Interstate 70S was renumbered as I-270 in 1973 when AASHTO mandated that all suffixed routes be dropped from the Interstate system. This left the original I-270 as Interstate 270 Spur, a designation that remains in place today.1

Plans for Interstate 70S envisioned a continuation of the route southward into the District of Columbia. Ultimately dropped, as were many other Washington urban freeways due to community opposition, I-270 ends at a wye interchange with the Capital Beltway opposite the exit with Maryland 355 (former U.S. 240 leading south into D.C.)

Interstate 270 scenes
Montrose Road meets Interstate 270 at a full-cloverleaf interchange by the Park Potomac master planned community. Initially the interchange was without the loop ramp onto Montrose Road west from I-270 north and the direct ramp from Montrose Road east onto I-270 south. Photo taken 08/04/13.
A loop ramp departs Montrose Road west to join the local lanes of Interstate 270 south ahead of the split with I-270 Spur. A second loop ramp follows from Montrose Road for Park Potomac Avenue. Photo taken 08/04/13.
Maryland 85 (Buckeystown Pike) northbound within the partial-cloverleaf interchange at Interstate 270 (Exit 31). The surface arterial meets the freeway adjacent to the Francis Scott Key Mall, south of Frederick. Photo taken 08/04/13.
Interstate 270 north ends one mile north of Maryland 85 at junction Interstate 70 and U.S. 40. U.S. 40 overtakes the freeway northward to U.S. 15 through Frederick while I-70 skims southern reaches of the city between Hagerstown and Baltimore. Photo taken 08/04/13.
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2 photos
The on-ramp to Interstate 270 north for U.S. 15 north and Interstate 70 & U.S. 40 departs Maryland 85 (Buckeystown Pike) north. Maryland 85 continues another mile north to Maryland 355 (Urbana Pike / historic U.S. 240) ahead of I-70 (Exit 54). Photos taken 08/04/13.
Spectrum Drive encircles Francis Scott Key Mall east from Maryland 85 (Buckeystown Pike) within vicinity of I-270. Photo taken 08/04/13.
Approaching Interstate 270 along Maryland 85 (Buckeystown Pike) south of Frederick. Originally a full-cloverleaf interchange joined the two routes, but the loop ramps from MD 85 to I-270 were removed. Photo taken 08/04/13.
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2 photos
Drivers depart Maryland 85 (Buckeystown Pike) south for the final mile of Interstate 270 north to Interstate 70, U.S. 15 and U.S. 40. Photos taken 08/04/13.
Passing under the Interstate 270 mainline, MD 85 nears the southbound on-ramp to Germantown, Gaithersburg, Rockville and Washington, DC. Photo taken 08/04/13.
Maryland 85 (Buckeystown Pike) continues south through additional retail areas from I-270 to a number of industrial parks ahead of Lime Kiln. I-270 angles southeast across the Monocacy River to Urbana. Photo taken 08/04/13.


  1. MDRoads: I-270

Photo Credits:

08/04/13 by AARoads

Connect with:
Interstate 70
Interstate 370
Interstate 495 - Capital Beltway
U.S. 40

Page Updated 06-07-2014.