title: Roadless space of the conterminous United States.
abstract: Roads encroaching into undeveloped areas generally degrade ecological and watershed conditions and simultaneously provide access to natural resources, land parcels for development, and recreation. A metric of roadless space is needed for monitoring the balance between these ecological costs and societal benefits. We introduce a metric, roadless volume (RV), which is derived from the calculated distance to the nearest road. RV is useful and integrable over scales ranging from local to national. The 2.1 million cubic kilometers of RV in the conterminous United States are distributed with extreme inhomogeneity among its counties.
authors.affiliation: U.S. Geological Survey (USGS), Fort Collins, CO 80526-8118, USA. rwatts@usgs.gov
authors.forename: Raymond D
authors.initials: RD
authors.lastname: Watts
authors.forename: Roger W
authors.initials: RW
authors.lastname: Compton
authors.forename: John H
authors.initials: JH
authors.lastname: McCammon
authors.forename: Carl L
authors.initials: CL
authors.lastname: Rich
authors.forename: Stewart M
authors.initials: SM
authors.lastname: Wright
authors.forename: Tom
authors.initials: T
authors.lastname: Owens
authors.forename: Douglas S
authors.initials: DS
authors.lastname: Ouren