The experimental and control group households had no statistically significant differences in vehicle CO2 emissions before the Expo Line opened, but after opening experimental group households had approximately 30% less vehicle CO2 emissions than control group households. That “after opening” difference is statistically significant
The accelerometer data allow us to measure physical activity in minutes of moderate or vigorous activity per day. After the Expo Line opened, those individuals living in the experimental neighborhoods who were the least physically active had the largest increases in physical activity relative to control group subjects. The Expo Line opening was associated with increases in physical activity among approximately the 40 percent of experimental subjects who had the lowest physical activity levels before the line opened. The impact was as high as 8 to 10 minutes of increased daily moderate or vigorous physical activity among those experimental group subjects who were the least active before the Expo Line opened. Note though that for more than half of the experimental group subjects (those more physically active before the Expo Line opened) our statistical test suggests that the Expo Line is associated with decreases in physical activity.
The impact of the Expo Line on VMT and rail ridership was larger near stations with more bus lines and near stations with streets with fewer traffic lanes, suggesting that bus service increases the impact of rail transit and that wide streets (which can be barriers to pedestrian access) reduce the impact of rail
transit, at least in the Expo Line corridor.