A massive effort to revamp the American air-traffic-control system from land-based to satellite-based equipment, dubbed NextGen, could result in greater flight efficiency and fuel cost savings at all major hubs by 2014, says Randolph Babbitt, Federal Aviation Administration chief. He also stressed the need for the next generation of land-side and air-side infrastructure. div id="articleExtrasA" div id="articleExtrasB" div id="articleExtras" Babbitt urged members of the American Association of Airport Executives last month in Dallas to work toward implementing multimodalism. “We have to advance our infrastructure to NextGen standards,” he said. “It’s the only way to keep pace with the rest of
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.