Table 4. Prediction models across all eight communities^a.

Predictorsa	EC2.5	EC0.2	PM2.5	PM0.2
Logged freeway CALINE4				0.059
Logged total CALINE4	0.255	0.291
Total length of roads in 50m buffer				0.074
Total length of roads in 100m buffer			0.039
Freeway truck count			0.041
Elevation			-0.039
Population density (300 m buffer)	0.050		0.037	0.071
Distance to point source of NOx (10-50 tons)				-0.048
Adjusted R2	0.53	0.51	0.27	0.16
Leave-one-out cross-validated (LOOCV) R2	0.51	0.49	0.21	0.12
Leave-one-community-out cross-validated (LOCOCV) R2	0.48	0.47	0.20	0.14

^aReported betas are scaled to two standard deviations of deviated predictors across all eight communities as follows: 1.6 units for logged freeway CALINE4, 1.1 units for logged total CALINE4, 116.7 meters for total length of roads in 50m buffer, 340.9 meters for total length of roads in 100m buffer, 6250 trucks for freeway truck count, 84.5 meters for elevation, 1574 individuals/km² for population density, and 3210 meters for distance to point source of NO_x (10-50 tons).