The bypass is expected to save drivers traveling between Phoenix and Las Vegas nearly 20 minutes -- and possibly hours during the worst traffic conditions, The Arizona Republic reported. The Nevada Department of Transportation will oversee daily operation of the bridge once finished. The Arizona Department of Transportation plans to open 15 miles of new four-lane divided highway leading to the bypass in time for the bridge opening, replacing a stretch of two-lane road.

An exact opening date has not yet been announced for the $114 million span, officially named the Mike O'Callaghan/Pat Tillman Memorial Bridge. The Federal Highway Administration said an opening gala will be held Oct. 16.

Approximately 890 feet above the Colorado River, the new bridge is the highest arched span in the Western Hemisphere. Thousands of tourists are expected to visit the site each year.

The new bypass will eliminate long traffic delays over the Depression-era Hoover Dam caused by a steep, tightly winding single-lane road. The new bridge will also allow freight trucks to take a more direct route to Las Vegas. After the Sept. 11, 2001, terrorist attacks, trucks were detoured 70 miles downriver away from the Hoover Dam.