title: The effect of reduced street lighting on road casualties and crime in England and Wales: controlled interrupted time series analysis.
abstract: BACKGROUND
  Many local authorities in England and Wales have reduced street lighting at night to save money and reduce carbon emissions. There is no evidence to date on whether these reductions impact on public health. We quantified the effect of 4 street lighting adaptation strategies (switch off, part-night lighting, dimming and white light) on casualties and crime in England and Wales.
  
  
  METHODS
  Observational study based on analysis of geographically coded police data on road traffic collisions and crime in 62 local authorities. Conditional Poisson models were used to analyse longitudinal changes in the counts of night-time collisions occurring on affected roads during 2000-2013, and crime within census Middle Super Output Areas during 2010-2013. Effect estimates were adjusted for regional temporal trends in casualties and crime.
  
  
  RESULTS
  There was no evidence that any street lighting adaptation strategy was associated with a change in collisions at night. There was significant statistical heterogeneity in the effects on crime estimated at police force level. Overall, there was no evidence for an association between the aggregate count of crime and switch off (RR 0.11; 95% CI 0.01 to 2.75) or part-night lighting (RR 0.96; 95% CI 0.86 to 1.06). There was weak evidence for a reduction in the aggregate count of crime and dimming (RR 0.84; 95% CI 0.70 to 1.02) and white light (RR 0.89; 95% CI 0.77 to 1.03).
  
  
  CONCLUSIONS
  This study found little evidence of harmful effects of switch off, part-night lighting, dimming, or changes to white light/LEDs on road collisions or crime in England and Wales.
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Steinbach
authors.affiliation: Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Chloe
authors.initials: C
authors.lastname: Perkins
authors.affiliation: Department of Security and Crime Science, University College London, London, UK.
authors.forename: Lisa
authors.initials: L
authors.lastname: Tompson
authors.affiliation: Department of Security and Crime Science, University College London, London, UK.
authors.forename: Shane
authors.initials: S
authors.lastname: Johnson
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Ben
authors.initials: B
authors.lastname: Armstrong
authors.affiliation: Department of Health Services Research, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Judith
authors.initials: J
authors.lastname: Green
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Chris
authors.initials: C
authors.lastname: Grundy
authors.affiliation: Department of Social and Environmental Health Research, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Wilkinson
authors.affiliation: Department of Population Health, London School of Hygiene & Tropical Medicine, London, UK.
authors.forename: Phil
authors.identifier: http://orcid.org/0000-0003-4431-8822
authors.initials: P
authors.lastname: Edwards
mesh_terms: D000063:Accidents, Traffic / Q000639:trends*; D058572:Carbon Footprint / Q000592:standards*; D003363:Cost Control; D003415:Crime / Q000639:trends*; D016208:Databases, Factual; D004739:England / Q000453:epidemiology; D006801:Humans; D065186:Interrupted Time Series Analysis; D008029:Lighting / Q000191:economics / Q000592:standards / Q000639:trends*; D016012:Poisson Distribution; D014852:Wales / Q000453:epidemiology
keywords: ACCIDENTS; Environmental epidemiology; SPATIAL ANALYSIS