md 175 begins just west of its bridges over the little patuxent river. the highway continues southwest as little patuxent parkway, the county-maintained six-lane divided highway that forms the main street of columbia town center. md 175 heads east as rouse parkway, a four-lane divided controlled access highway; the highway was renamed from little patuxent parkway to honor columbia founder james rouse and his wife patty in 2006. the highway immediately has a cloverleaf interchange with us 29 (columbia pike). md 175 heads southeast through intersections with thunder hill road, tamar drive, and dobbin road as it passes between the columbia villages of oakland mills to the southwest and long reach to the northeast. the state highway expands to six lanes at dobbin road and has a partial cloverleaf interchange with snowden river parkway that provides access to a park and ride lot serving mta maryland commuter buses and a trumpet interchange with columbia gateway drive. access from eastbound md 175 to columbia gateway drive requires using the snowden river parkway interchange. md 175 widens to eight lanes at columbia gateway drive, a width the highway carries through its intersection with the eastern end of md 108 (waterloo road) to the highway's partial cloverleaf interchange with i-95. the highway's name changes from rouse parkway to waterloo road at the md 108 junction. md 175 has six lanes from i-95 to east of its junction with us 1 (washington boulevard), which was the site of a tavern called waterloo and before that spurrier's tavern.