Key: R = revised.
Notes: These data cover wetlands acreage affected by Federal-Aid Highway projects, approximately 24% of the total mileage of U.S. public roads. These data are collected by states using varying collection methodologies. The mitigation ratio equals acres mitigated to acres impacted. Acres gained data have been revised for 2006. 2000-05 data are adjusted to represent all 50 states, based on the proportion of reporting states. 2006 data is based on 17 states' responses. 2007 data is based on 34 states' responses.
Sources: 2000-2004-U.S. Department of Transportation, Federal Highway Administration, Federal Highway Administration Wetland Mitigation Performance Measure for Federal-Aid Highway Projects Fiscal Year (FY) 2004, available at http://www.fhwa.dot.gov/environment/perform/ as of November 2008. 2005-2007-USDOT, FHWA, personal communication, August 2007 and September 2009.