Moving with the Times: Designing Bridges that are Beautiful, Structurally-Efficient and Economical

This article discusses the fundamental design changes that have occurred in United States bridge project development over the last decade. According to the author, bridge projects have evolved from being a matter of choosing the appropriate structure members or ensuring that the structure properly resists specified loads. Today projects are analyzed in a more complete context, with a large emphasis placed on aesthetics. Beyond meeting the needs of clients, bridge engineers must now consider the needs of the general public who have become legitimate stakeholders. The public's perception of value involving certain aesthetic design qualities now has a profound influence on client funding of bridge projects. Another part of the evolution in bridge design involves implementing the new load and resistance factor design specifications (LRFD), as mandated by the Federal Highway Administration. To comply with new FHWA rules, all new federal-aided bridge projects where states initiate the preliminary engineering after October 1, 2007 must be designed to AASHTO LRFD design specifications. All bridge design elements are affected, including foundations, substructures, and superstructures.