Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Airport Improvement Program is a United States federal grant program that provides funds to airports to help improve safety and efficiency. Improvement projects relate to runways, taxiways, ramps, lighting, signage, weather stations, NAVAIDs, land acquisition, and some areas of planning. The money is raised through taxes on airplane tickets sold to the public and a tax on aviation fuel. In 2009, funds under the program went to 389 airports used by airlines to offer scheduled passenger service, and to 1,121 general-aviation airports in communities with no airline service.