each way at all other times. One dividing lane is closed to traffic at all times, and motorcycles are permanently prohibited from using the central, red-surfaced lane (with a fixed sign) owing to its use as an off-camber drain. The lane control signals can be set to allow travel in either direction for any lane in exceptional circumstances, which has been used for single-lane, reduced-speed running in each direction (or 2+1 with no divider) during road work, allowing the expressway to remain largely open even during major repairs. However, the 7-lane section splits at both ends to fully divided sets of 4x2 lane slip roads, with the central red lane ending in a barrier, so full use of this flexibility is uncommon and occasional overnight closure is required. U.S. Route 78 in Snellville, Georgia, United States, has 6 lanes in total. This occurs from the limited access portion through Stone Mountain Park to Georgia State Route 124 (Scenic Highway) for several miles. The middle two lanes were reversible (usually occurring during rush hour) with a varying lane always reserved as a center turn lane; hence 3 lanes were used for one direction of travel and 2 for the other. However, due to rising traffic volumes during peak hours that made traffic flows equivalent, the reversible lane system was removed in 2009. The Caldecott Tunnel between Oakland, California and Contra Costa County, previously had three separate bores, with the middle bore switching direction twice daily for rush hour traffic. A fourth tunnel bore opened in November 2013 to westbound traffic. Two bores are now permanently used by westbound traffic, and the other two by eastbound traffic, with no reversible lanes. The Elbe Tunnel near Hamburg, Germany, is part of the Bundesautobahn A7 and has four separate bores, of which two can be switched to allow travel either in each direction or unidirectionally. Lane controls and physical separation by movable barrier Benjamin Franklin Bridge, Walt Whitman Bridge, and Commodore Barry Bridge in Philadelphia Tappan Zee Bridge (1955) in New York Theodore Roosevelt Bridge in Washington, D.C. Auckland Harbour Bridge in Auckland, New Zealand San Diego-Coronado Bay Bridge in San Diego, California (part of California Route 75) Southeast Expressway in and near Boston, Massachusetts A reversible lane, also called a zipper lane, is in use on eastbound Interstate H-1 for traffic heading from Leeward Oahu to Pearl Harbor. It is open from 5:30