Central Federal Lands Highway Division

Hoover dam bypass┬áThe dangerous approach to one of the WestÔÇÖs engineering marvels will soon be less so, thanks to a new bridge spanning Black Canyon nearly 900 feet above the Colorado River. Andrew Pelis reports. Traffic congestion has become a way of lifeÔÇöbut at a cost. US 93 near the Hoover Dam in Nevada, for instance, has long been identified as a recipe for potential disaster because of the volume of traffic negotiating its sharp bends.If anything did happen, it would be a tragedy not only for the people caught up in it, but could also inflict millions of dollars in damage to the dam and its facilities, contaminate the waters of Lake Mead or the Colorado River, and interrupt the power and water supply for millions of people in the Southwest.Congestion problems caused by the inadequacy of the existing highway across the dam already impose a serious economic burden on the states of Arizona, Nevada and Utah. US 93 was identified as a high-priority corridor in the National Highway System Designation Act of 1995.Consequently, the Central Federal Lands Highway Division (CFLHD) was called in to develop an alternate crossing of the river near the Hoover Dam, resulting in the removal of through-vehicle and truck traffic. This new route will eliminate the problems with the existing roadwayÔÇösharp turns, narrow roadways, inadequate shoulders, poor sight distance and low travel speeds.The CFLHD operates as part of the Federal Lands Highway Program, administering the surveying, design and construction of forest highway road systems, parkways and park roads, Indian reservation roads, defense access roads and other Federal lands roads in the central United States, Hawaii and American Samoa. The Hoover Dam Bypass project aims to minimize the risk of accidents on the dam crest and the Nevada and Arizona approaches to the dam, and also to remove a major bottleneck to interstate and international commerce and travel in the West. An integrated team of professionals from HDR Engineering, T.Y. Lin International, Sverdrup Civil, Inc. and several supporting sub-consultants make up the consultant team collectively known as the Hoover Support Team. Their work included design of roadways, bridges, tunnels, wildlife underpasses and overpasses, utility design, high-capacity transmission tower relocations and a signature long-span bridge over the Colorado River.┬á In August 2001 the design phase of the Hoover Bypass Project began. Earlier studies and environmental evaluations had identified the Sugarloaf Mountain Roadway Alignment as the preferred alternative, and the new roadway alignment will begin near the Hacienda Hotel and Casino on the Nevada side and follow a route just south of existing US 93 to the Reclamation warehouse area. Funding for the project comes from a number of sources with TEA-21 (the Transportation Equity Act for the 21st Century) providing $41 million under the High Priority Projects Program. Arizona and Nevada have each agreed to contribute $20 million to the proposed project, and it has received $31.5 million in Public Lands Highway Discretionary (PLHD) funding, $4 million in National Corridor Planning and Development (NCPD) Program funding, $23 million in USDOT appropriations and $5 million in the 2003 Consolidated Appropriations Resolution. The revised project cost is $234 million including project engineering and construction. Coordinating all aspects of the project has proven a considerable challenge, particularly given the number of organizations involved. That said, progress remains steady and the joint venture contractor building the River Bridge, Obayashi Corporation and PSM Construction USA, is advancing construction of the 1,060-foot twin-rib concrete arch. The joint venture completed the design, fabrication and erection of the new highline system in January 2008. Upcoming work includes erecting two precast, segmental temporary towers at the ends of the approach span decks to anchor the cable support system for continued arch construction. Construction of the arch is expected to take approximately 14 months, with completion scheduled in September 2009. The fourth phase of the Hoover Dam Bypass project is now complete. The interim surfacing project was awarded to Las Vegas Paving Corporation in December 2007 and was completed in June of this year.The final phase will include the short sections of remaining roadway tie-ins to the River Bridge and US 93, as well as signing, striping, barriers and pedestrian facilities on the entire bypass. ┬á