Bureau of Transportation Statistics (BTS)

Table 2
Weighted Least Squares Models of VMT

Dependent variable: annual VMT Beta SE t-stat P-value
Constant 9,979 174.7 57.12 0.000
Population density –0.151 0.009 –16.21 0.000
Income per household member 4.01E-02 0.003 12.72 0.000
Vehicle age –408.0 8.753 –46.62 0.000
HH members per vehicle owned 1,883 84.55 22.27 0.000
LDT indicator 1,162 1,11.0 10.47 0.000

Adjusted R2: 0.123
Number of observations: 26,398 vehicles
Weighted by: 1/household size
Model form: VMT = β′χ + ε, where ε ~ N(0, σ2 x household size)

Dependent variable: annual VMT Beta SE t-stat P-value
Constant 10,043 175.0 57.40 0.000
Population density –0.153 0.009 –16.30 0.000
Income per household member 4.00E-02 0.003 12.60 0.000
Vehicle age –405.4 8.76 –46.20 0.000
HH members per vehicle owned 1,821 85.2 21.40 0.000
SUV indicator 1,027 189 5.44 0.000
Pickup indicator 721.7 152 4.74 0.000
Minivan indicator 2,150 202 10.60 0.000

Adjusted R2: 0.125
Number of observations: 26,398 vehicles
Weighted by: 1/household size
Model form: VMT = β′χ + ε, where ε ~ N(0, σ2 x household size)

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