A DOT selects the 10 intersections with the highest number of crashes in the past year for installing red light cameras. A sample of the 10 intersections with the lowest number of crashes in the past year was selected as control group with no red light cameras. It was observed that the number of crashes at the 10 intersections with the red light cameras dropped considerably the next year while the number of crashes at the control group increased the next year. This shows that red light cameras are effective in reducing crashes. False True