Related Links: Obama Rolls Out $302-Billion Transportation Bill Proposal (ENR 3/10/2014 issue) [subscription] Boxer Seeks to Unveil New Transportation Bill in April (enr.com 2/18/2014) [subscription] Senate Environment and Public Works Committee Chairman Barbara Boxer (D-Calif.) is moving ahead with the highway-policy portion of a draft new surface-transportation legislative package.Boxer said at a March 27 committee hearing on transportation matters that she would discuss the envisioned bill with the rest of the panel's "Big Four" the week of March 31. Those other senators are David Vitter (La.), the committee's top Republican; Thomas Carper (D-Del.), transportation and infrastructure subcommittee chair; and John
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.