title: Increased traffic accident rates associated with shale gas drilling in Pennsylvania.
abstract: OBJECTIVE
  We examined the association between shale gas drilling and motor vehicle accident rates in Pennsylvania.
  
  
  METHODS
  Using publicly available data on all reported vehicle crashes in Pennsylvania, we compared accident rates in counties with and without shale gas drilling, in periods with and without intermittent drilling (using data from 2005 to 2012). Counties with drilling were matched to non-drilling counties with similar population and traffic in the pre-drilling period.
  
  
  RESULTS
  Heavily drilled counties in the north experienced 15-23% higher vehicle crash rates in 2010-2012 and 61-65% higher heavy truck crash rates in 2011-2012 than control counties. We estimated 5-23% increases in crash rates when comparing months with drilling and months without, but did not find significant effects on fatalities and major injury crashes. Heavily drilled counties in the southwest showed 45-47% higher rates of fatal and major injury crashes in 2012 than control counties, but monthly comparisons of drilling activity showed no significant differences associated with drilling.
  
  
  CONCLUSIONS
  Vehicle accidents have measurably increased in conjunction with shale gas drilling.
authors.affiliation: Center for Health Research, Geisinger Health System, Danville, PA, USA. Electronic address: jhgraham1@geisinger.edu.
authors.forename: Jove
authors.initials: J
authors.lastname: Graham
authors.affiliation: Weis Center for Research, Geisinger Health System, Danville, PA, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Irving
authors.affiliation: Center for Health Research, Geisinger Health System, Danville, PA, USA.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Tang
authors.affiliation: Weis Center for Research, Geisinger Health System, Danville, PA, USA.
authors.forename: Stephen
authors.initials: S
authors.lastname: Sellers
authors.affiliation: Weis Center for Research, Geisinger Health System, Danville, PA, USA.
authors.forename: Joshua
authors.initials: J
authors.lastname: Crisp
authors.affiliation: Department of Orthopedics, Geisinger Health System, Danville, PA, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Horwitz
authors.affiliation: Resources For the Future, Washington, DC, USA; Department of Economics, University of Calgary, Calgary, Canada.
authors.forename: Lucija
authors.initials: L
authors.lastname: Muehlenbachs
authors.affiliation: Resources For the Future, Washington, DC, USA.
authors.forename: Alan
authors.initials: A
authors.lastname: Krupnick
authors.affiliation: Weis Center for Research, Geisinger Health System, Danville, PA, USA.
authors.forename: David
authors.initials: D
authors.lastname: Carey
mesh_terms: D000063:Accidents, Traffic / Q000401:mortality* / Q000706:statistics & numerical data*; D005579:Fossil Fuels; D006801:Humans; D008137:Longitudinal Studies; D018986:Motor Vehicles; D000066388:Oil and Gas Industry; D010414:Pennsylvania / Q000453:epidemiology; D012044:Regression Analysis; D012189:Retrospective Studies; D014947:Wounds and Injuries / Q000453:epidemiology*
chemical_list: D005579:Fossil Fuels
keywords: Marcellus; Motor vehicle accidents; Traffic; Unconventional natural gas