|
George Washington Memorial Parkway Virginia, Maryland, Washington, D.C.
The riverfront location helped cut down on intersections and offered excellent opportunities for park development, but it required the construction of numerous bridges and over two-and-a-half miles of artificial causeway. Large sections of the parkway near Hunting Creek and between Washington and National Airport are built entirely on landfill dredged from the bottom of the Potomac River. Most of the original highway surface was composed of reinforced concrete slabs, but flexible asphalt was used on filled land to avoid cracking when the excavated material settled. In Alexandria, the concrete pavement was covered with blacktop. These distinctions can still be seen on today's parkway. The unstable fill also required innovative planting techniques and strongly braced bridge construction at Boundary Channel and other stream crossings.
Most of the original parkway bridges were reinforced concrete structures faced with rough-cut stone for a more traditional appearance. Each bridge was given a slightly different design to accommodate local conditions and provide picturesque variety. This was standard procedure for parkway design in the 1920s-1930s. Railroad regulations stipulated steel construction, so parkway designers arched the railroad overpass's steel girders to harmonize with the other parkway bridges. The exposed concrete and steel spans of the parkway's later bridges exemplify modernist aesthetics and engineering concerns.
| Introduction | Acadia | Blue Ridge Parkway | Chickamauga and Chattanooga | Colonial Parkway | Generals Highway | George Washington Memorial Parkway | Great Smoky Mountains | Mount Rainier | Rock Creek and Potomac Parkway | Shenandoah's Skyline Drive | Southwest Circle Tour | Vicksburg | Yellowstone | Yosemite | |