Remember the kid game,
Red light, green light, dynamite Boom! ?
Bummer. You must have led a sheltered childhood.
Anyway, it was a flawed game because it didn't have a yellow light. And yellow lights are what makes the world go 'round say the traffic engineers.
The yellow light governs how smoothly traffic flows through the intersection. If the yellow is too long, too many cars dangerously crowd the intersection. Too short and drivers get caught on camera 'running the red.'
Federal guidelines say yellow lights must last between 3 and 6 seconds. Getting it right to the half-seond would cut red light violations in half. It's a tricky equation however because there are so many variables--speed limit, volume of traffic, grade of the roadway, weather condition, time of day, impatience of the driver, etc.
Studies say ideally you need 4.5 seconds for the perfect yellow. If only 3 seconds are provided, drivers would either have to stop abruptly or proceed through and risk running the red. So getting it "just right" is all of the above plus safety.
A waiting driver's response to the green light is one second. So proper acceleration is another vital factor.
FYI: Top fuel racers can hit 100 mph in about 4/5ths of a second.
Now when you time a yellow for Tony and his friends, you really do have to get it just right.
|Schumacher's Top Fuel car|
My road to riches is to come up with 'the golden formula' that produces safe, smooth driving. Can you imagine what saving one second of time for every car at every intersection in the world would do for saving gas? I figure that instead of self-driving cars, we develop self-driving Top Fuel racers. We would not only save an incredible amount of gas and time but we would be able to get from Chicago to New York in less than a minute, not counting bathroom stops.