After enduring 12 extensions before the Safe Accountable, Flexible, Efficient Transportation Equity Act—a Legacy for Users became law in 2005, state departments of transportation and construction companies see the troublesome cycle repeating. SAFETEA-LU lapsed on Sept. 30, and they’re already on stopgap No. 2. A newly enacted spending package authorizes highway and transit programs through Dec. 18. Beyond that, another extension, probably measured in months, not years, is virtually assured. The spending measure, which President Obama signed on Oct. 30, also provides full fiscal 2010 appropriations for Interior Dept. and Environmental Protection Agency programs. In addition, it extends funding through
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.