The Speedlight is a speedometer mounted on the rear of a vehicle. It displays the speed of the vehicle to the traffic behind it and visually distinguishes the difference between parked, stopped, standing, deceleration, acceleration, panic stop, riding the brake, riding the turn indicator or a vehicle involved in an accident. And it does it, instantaneously. There is also a miniature version of the Speedlight mounted high on the instrument cluster of vehicles so drivers can compare their Speedlight to the Speedlights in front of them as well.

This is accomplished through an easy to “read” horizontal series of red LED lights on the back of the vehicle similar to a third brake light. It’s activated, or turned on, whenever the vehicle is running. It illuminates at low intensity or running light intensity. Upon braking it illuminates at high intensity or brake light intensity. The number of lights to illuminate is relative to the speed of the vehicle. If the vehicle is at a complete stop the entire series of lights illuminates. If the vehicle is going very fast only a few of the lights on each end, the far left and far right, will be illuminated. As the vehicle speed decreases during coasting or braking more lights sequentially illuminate in from both ends towards the middle making each individual light longer and the distance between them less. The speed that the two lights “grow together” lets the following traffic see how fast the vehicle is slowing down. When the vehicle comes to a complete stop the entire light strip illuminates connecting the two lights into one solid line indicating that the vehicle is completely stopped.

In the center of the Speedlight there is one light called the Panic Light. For increased visibility it’s orange and much larger than the red lights in the strip. The Panic Light is on low intensity whenever the Speedlight is on. There are only two times when the Panic Light goes to high intensity. One is during a “panic stop” and the other is when the vehicle is completely stopped. A panic stop is when a vehicle is braking very hard and decelerating very fast. The threshold for panic deceleration is set at 15 mph per second. This is faster deceleration than what occurs in most normal driving conditions and fast enough that the following traffic should be warned and prepared to respond.

The Panic Light also illuminates at high intensity when the vehicle is completely stopped. This is extremely valuable when approaching a stopped vehicle quickly as can happen around a curve or under circumstances where there is little time to react.