The S.M.A.R.T. is a device that counts vehicles, clocks vehicle speed, and visually notifies the driver of the speed. The data collected by the S.M.A.R.T. is used to determine the 85th percentile speed of traffic. The 85th percentile speed is a nationally recognized measure of what is considered proper speed for the normally careful and competent actions of a reasonable person. It is the speed at or below which the 85% of the observed traffic is moving.