title: A global strategy for road building.
abstract: The number and extent of roads will expand dramatically this century. Globally, at least 25 million kilometres of new roads are anticipated by 2050; a 60% increase in the total length of roads over that in 2010. Nine-tenths of all road construction is expected to occur in developing nations, including many regions that sustain exceptional biodiversity and vital ecosystem services. Roads penetrating into wilderness or frontier areas are a major proximate driver of habitat loss and fragmentation, wildfires, overhunting and other environmental degradation, often with irreversible impacts on ecosystems. Unfortunately, much road proliferation is chaotic or poorly planned, and the rate of expansion is so great that it often overwhelms the capacity of environmental planners and managers. Here we present a global scheme for prioritizing road building. This large-scale zoning plan seeks to limit the environmental costs of road expansion while maximizing its benefits for human development, by helping to increase agricultural production, which is an urgent priority given that global food demand could double by mid-century. Our analysis identifies areas with high environmental values where future road building should be avoided if possible, areas where strategic road improvements could promote agricultural development with relatively modest environmental costs, and 'conflict areas' where road building could have sizeable benefits for agriculture but with serious environmental damage. Our plan provides a template for proactively zoning and prioritizing roads during the most explosive era of road expansion in human history.
authors.affiliation: Centre for Tropical Environmental and Sustainability Science, and College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland 4878, Australia.
authors.forename: William F
authors.initials: WF
authors.lastname: Laurance
authors.affiliation: 1] Centre for Tropical Environmental and Sustainability Science, and College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland 4878, Australia [2] Kenyir Research Institute, Universiti Malaya Terengganu, 21030 Kuala Terengganu, Malaysia.
authors.forename: Gopalasamy Reuben
authors.initials: GR
authors.lastname: Clements
authors.affiliation: Centre for Tropical Environmental and Sustainability Science, and College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland 4878, Australia.
authors.forename: Sean
authors.initials: S
authors.lastname: Sloan
authors.affiliation: Institute on the Environment, and Department of Ecology, Evolution, and Behavior, University of Minnesota, Saint Paul, Minnesota 55108, USA.
authors.forename: Christine S
authors.initials: CS
authors.lastname: O'Connell
authors.affiliation: Center for the Environment, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Nathan D
authors.initials: ND
authors.lastname: Mueller
authors.affiliation: Centre for Tropical Environmental and Sustainability Science, and College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland 4878, Australia.
authors.forename: Miriam
authors.initials: M
authors.lastname: Goosem
authors.affiliation: Centre for Tropical Environmental and Sustainability Science, and College of Marine and Environmental Sciences, James Cook University, Cairns, Queensland 4878, Australia.
authors.forename: Oscar
authors.initials: O
authors.lastname: Venter
authors.affiliation: Department of Animal and Plant Sciences, University of Sheffield, Sheffield S10 2TN, UK.
authors.forename: David P
authors.initials: DP
authors.lastname: Edwards
authors.affiliation: Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
authors.forename: Ben
authors.initials: B
authors.lastname: Phalan
authors.affiliation: Department of Zoology, University of Cambridge, Cambridge CB2 3EJ, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Balmford
authors.affiliation: Australian Research Centre for Urban Ecology, and School of Botany, University of Melbourne, Melbourne, Victoria 3010, Australia.
authors.forename: Rodney
authors.initials: R
authors.lastname: Van Der Ree
authors.affiliation: Conservation Strategy Fund, 663-2300 Curridabat, San José, Costa Rica.
authors.forename: Irene Burgues
authors.initials: IB
authors.lastname: Arrea
mesh_terms: D000818:Animals; D044822:Biodiversity; D003247:Conservation of Natural Resources; D058735:Environmental Policy; D005843:Geography; D007391:International Cooperation; D008962:Models, Theoretical