Mr. Cantrell has recently finished a stoplight that will be used in the braking competition. The red light is triggered when the car crosses the "Braking Line" and will be triggered at the same time for each car. Along with a red light, vehicle speed will be measured 2" before the Braking Line, obtaining the vehicles exact speed before it begins braking. A green light will signal the next vehicle to begin the competition.
from Kearney 5-1-10