Washington's Bridge Inventory
As reported in the Gray Notebook's Bridge Annual Update, WSDOT's inventory of vehicle bridges increased from 2,978 to 2,990 since June 2006. The increase is due to new bridges being built and older bridges being replaced within the highway system. WSDOT constructed 99 vehicle bridges in excess of 20 feet in length from 2002 to 2006, an average of about 20 per year. During the same period, the number of vehicle bridges under 20 feet in length increased from 263 to 325. Concrete structures represent approximately 78 percent of all WSDOT bridges, as compared to 21 percent steel and one percent wood. The average age of all WSDOT bridges is 40 years old. More details on this topic and other key issues can be found in the June 2007 Gray Notebook at: www.wsdot.wa.gov/accountability.