摘要: |
The stretch of Route 93 leading up to and over Hoover Dam is a dangerous, overburdened bottleneck ripe for a major transportation disaster, and the dam's overseers and area transportation engineers would like to create a high-speed bypass that would drain away from the dam all but sightseeing traffic. In 1989, the Bureau of Reclamation established the Colorado River Bridge Project Management Team (PMT), which addressed environmental concerns and engineering problems inherent in a number of bypass proposals. Within a year, PMT had come up with three bypass proposals: Promontory Point, a 5.8-km stretch of new highway and a 670-m cablestayed or steel truss rib-through-arch bridge about 300 m upstream of Hoover Dam; Sugarloaf Mountain, a 5.3-km stretch of new highway and a 580-m steel arch or cablestayed bridge 460 m downstream of Hoover Dam; and Gold Strike Canyon, a 5.3 km stretch of new highway and a 520-m steel arch or concrete deck arch bridge about 1.6 km downstream of Hoover Dam. Just as PMT was ready to move forward with a design proposal, the mission of the Bureau of Reclamation changed and funding dried up. In 1995, the Hoover Dam Bypass project was officially placed on hold. In early 1997, state and federal leaders from Nevada and Arizona appealed to the U.S. Department of Transportation for funding assistance; and in May 1997, the Federal Highway Administration's (FHWA) Central Federal Lands Highway Division was named as the lead agency to resume the Hoover Dam Bypass project. In December 1998, PMT selected the Sugarloaf Mountain alternative. FHWA is proceeding with the Final Environmental Impact Statement, which is scheduled to be completed in the summer of 1999. Funding for the construction remains a major hurdle. Although the new bridge will have its critics--especially those who will argue that the bridge mars dam visitors' views of Black Canyon--the bypass will ultimately improve traffic flow, reduce air and noise pollution, eliminate the threat of a serious accident on or near Hoover Dam, and improve the visitor's overall experience. |