President Obama has directed the U.S. Environmental Protection Agency and the U.S. Dept. of Transportation to create a first-ever national policy to increase fuel economy and likewise decrease greenhouse-gas emissions for medium- and heavy-duty trucks. Photo: Dawes Rigging & Crane Rental Inc. Fuel-economy regulations are coming for heavy construction trucks. This new directive, signed on May 21 and impacting model years 2014-2018, comes about a month after EPA and the National Highway Traffic Safety Administration (NHTSA) had finalized similar rules for passenger cars and light trucks that will be manufactured in 2012-2016. Large trucks consume more than 2 million barrels
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.