The Bureau of Transportation Statistics (BTS), a part of DOT's Research and Innovative Technology Administration (RITA), presents State Transportation Statistics 2006, a statistical profile of transportation in the 50 states and the District of Columbia. This is the fourth annual edition of the State Transportation Statistics and a companion document to the National Transportation Statistics (NTS), which is updated quarterly on the BTS website. Like the previous editions, this document presents transportation information from U.S. DOT, other federal government agencies, and other national sources. A picture of the states' infrastructure, freight movement and passenger travel, safety, vehicles, economy and finance, and energy and the environment is presented in tables covering the 50 states and the District of Columbia. Tables have been updated with the most recent data available. Included in this State Transportation Statistics 2006 report is a description of the data sources used; information on data formats; federal, state, and national data sources; and a glossary of terms. Also contained in this publication is a summary table that displays the approximate timing of future data releases and contact information for each state's department of transportation.