State and local transportation officials as well as firms that design and build roads and subway projects now have a bit more market stability, thanks to a newly enacted measure that extends federal highway and transit programs through Sept. 30, the last day of the 2011 fiscal year. The bill, which President Obama signed on March 4, freezes funding at fiscal 2010 levels for about seven months. The new measure’s highway obligation limit will be about $24 billion, or roughly 7/12ths of 2010’s full-year obligation ceiling of $41.1 billion. The legislation is the latest—and the second-longest—of seven extensions since Sept.
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.