As the lame-duck congressional session continues, a further extension for federal highway and transit programs looks more and more likely. The current short-term surface-transportation authorization expires on Dec. 31. Signals have emerged that another stopgap is in the cards. Senate Environment and Public Works Committee Chairman Barbara Boxer (D-Calif.) told reporters after a Nov. 17 hearing that she is working on a highway-bill extension that would run through the middle of 2011. Boxer’s panel has jurisdiction over highways; other Senate committees oversee transit and highway safety. With a multiyear bill almost certainly dead for the year, outgoing House Transportation and
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.