Table 1

Values used in the Markov model evaluating NSZs relative to the no intervention

Cost (2016 US$)
 Cost of injury (per case)
  Lifetime medical cost due to non-fatal traffic injury3608902GammaCDC26
  Lifetime medical cost due to fatal traffic injury16 2654066GammaCDC26
  Lifetime productivity cost due to non-fatal traffic injury66821671GammaCDC26)
  Lifetime productivity cost due to fatal traffic injury1 277 926319 482GammaCDC26
 Intervention cost (per person)
  Proposed speed bumps1.300.32GammaBushell et al 24
  Existing speed bumps0.350.09GammaBushell et al 24
  Gateways0.600.15GammaBushell et al 24
  20 mph markings0.280.07GammaBushell et al 24
Health utility decrement
 Serious traffic injury0.45Low: 0.36; high: 0.53TriangularEQ5D survey
 % Case fatality ratio of traffic injury0.380.02BetaNYS Department of Motor Vehicles21
 % Serious injury among non-fatal injuries7.540.13BetaNYS Department of Motor Vehicles21
 % Background traffic injury probability0.150.01BetaNYC Department of Transportation17, NYS Department of Motor Vehicles21
 % Traffic injury reduction in the NSZs8.74Low: 1.02; high: 16.47Triangular
 % Potential injury increase in control neighbourhoods0.31Low: −3.64; high: 4.27Triangular
 Baseline age36NYC Department of City Planning15
 Time horizon54
 % Discount rate3%Low: 0%; high: 5%TriangularPaulden et al 16
 Frequency of NSZs reconstruction (every n years)5Low: 3; high: 7Triangular
 Population in NSZs518 420NYC Department of City Planning18
  • EQ5D, EuroQol Five Dimensions Questionnaire; NSZ, neighbourhood slow zone; NYC, New York City; NYS, New York State SE, standard error