Table 7 |
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Sensitivity analyses including best predictor in each category, all summary measures. |
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Indicator Type |
Traffic Indicator |
Estimate(s), p-value(s) from multivariate model |
Model R2 |
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Null model |
R2 = .39 |
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Cumulative density scores: |
Unweighted traffic density in 100 m * Obs nearest Major Road (n = 50) |
β1 = 0.055 (.004) β2 = -0.051 (.004) |
R2 = .55 |
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Kernel-weighted density in 50 m * Obstructed (n = 50) |
β1 = 0.034 (.02) β2 = -0.056 (.002) |
R2 = .55 |
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Density of urban roads (>8500 cars/day) in 200 m * Obstructed (n = 50) |
β1 = 589.4 (.049) β2 = -760.9 (.0095) |
R2 = .52 |
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Summary measures: |
Total roadway length within: |
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50 meters * Obstructed (n = 50) |
β1 = 0.0144 (<.0001) β2 = -0.0094 (.005) |
R2 = .56 |
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100 meters * Obstructed (n = 50) |
β1 = 0.0022 (.34) β2 = -0.0042 (.005) |
R2 = .54 |
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200 meters * Obstructed (n = 50) |
β1 = 9.28*10-4 (.22) β2 = -1.25*10-3 (.008) |
R2 = .52 |
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300 meters * Obstructed (n = 50) |
β1 = 2.31*10-4 (.55) β2 = -6.65*10-4 (.0095) |
R2 = .50 |
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Vehicle Miles Traveled in 200 m * Obstructed (n = 50) |
β1 = 1*10-7 (.21) β2 = -1*10-7 (.10) |
R2 = .47 |
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Distance-based measures: |
To nearest highway (>19,000/day) * Obstructed (n = 50) |
β1= 0.0176 (.12) β2 = -0.0195 (.07) |
R2 = .50 |
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Characteristics of nearest major road: |
Trucks per day on nearest major road * Obstructed (n = 34) |
β1 = .0061 (.01) β2 = .00596 (.01) |
R2 = .59 |
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Final model bolded; models with diesel-based terms italicized. Traffic indicators for NO2. |
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Clougherty et al. Environmental Health 2008 7:17 doi:10.1186/1476-069X-7-17 |
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