U.S. Transportation Secretary Ray LaHood dedicated a new bypass bridge at the Hoover Dam Thursday. When it opens next week, truckers will no longer have to take a 75-mile detour.

U.S. 93, which runs over the dam on a congested two-lane, is a high-priority trade corridor and is a central part of the major transportation network in the western United States. Due to increases in commercial freight shipments to and from southern California, and population booms in Las Vegas and Phoenix, the road over the Hoover Dam became progressively more congested.

Security concerns after Sept. 11, 2001, led authorities to ban commercial trucks from traveling across the dam, forcing truck drivers on the route to use a 75-mile detour. The new Hoover Dam Bypass will shorten the route for commercial trucking along this corridor and reduce traffic congestion.

With more than a thousand of the workers who helped build it looking on, LaHood dedicated the Mike O'Callaghan-Pat Tillman Memorial Bridge. It will be the western hemisphere's longest single-span concrete arch bridge and one of the tallest in the world.

"This magnificent bridge is proof positive that America is not afraid to dream big," said Secretary LaHood. The 1,900-foot-long bridge is part of a $240 million four-lane bypass that will reroute traffic for 3.5 miles from the two-lane bottleneck on U.S. 93 across the Hoover Dam.

Planning for the Hoover Dam Bypass began in the late 1980s, though construction didn't begin until 2002 on the project, located on the Arizona/Nevada state line about 40 miles east of Las Vegas.