U.S. Department of Transportation, Federal Highway Administration, Office of Bridge Technology. National Bridge Inventory 2017, Deficient Bridges by State and Highway System.
Association of State Dam Safety Officials. Calendar Year 2017 Data from 2018 State Dam Safety Program Performance Questionnaire. 2019.
U.S. Army Corps of Engineers. Calendar Year 2018 Data from 2018 National Inventory of Dams. 2019.
U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics. State Transportation Statistics 2015. Table 1-16: Inland Waterway Mileage: 2013. 2015.
U.S. Federal Emergency Management Agency. Midterm Levee Inventory. 2017.
U.S. Army Corps of Engineers. National Levee Database. 2017.
U.S. Department of Transportation, Federal Highway Administration. Highway Statistics 2017, Table HM-10: Highway Statistics 2017, Public Road Length – 2017. 2019.
TRIP. State Information and Reports: 2017. 2019. Road condition information from TRIP is based on data submitted by state Departments of Transportation to the Federal Highway Administration, using the International Roughness Index. State DOTs may also have their own internal pavement management systems for the roads and highways that they maintain. As a result, the data may not be identical but should be viewed as complimentary.