Ever wonder why traffic lights are red, yellow, and green — and how to beat them? Audi has you covered.

I’ve long been amazed by traffic lights. That seems like a pretty dumb thing to say, for sure, but think about it: in a world where daily life can be incredibly chaotic, how did we manage to implement a system based off of three colors that (most) everyone seems to understand and respect? It’s kind of odd, right? Road safety and the timing of people’s movements throughout their city/town are essentially based on a simple system of three colors — something a pre-schooler could understand. Yet to make a business deal, one needs a 1,065-column Excel. The world is weird sometimes.

I had never thought to ask why those were the three colors, so I did some research and came across a ton of other interesting -ish, which I’ll now present briefly. Here’s why they’re red, yellow, and green: it started in the railroad industry (about the 1830s) as red (stop), white (go) and green (caution). This caused issues because the holders for green/red were, in fact, white. If the red/green colors fell out, white would be exposed — so “stop” would look like “go.” This caused train accidents, as you’d imagine. In 1865 in London, and again in 1920 in Detroit, different systems were experimented with for moving along traffic. The Detroit system, created by William Potts, is thought to be the first of the modern traffic lights. (The intersection was Woodward and Michigan.) Potts had no patent for the light, built it for $37, and was generally recognized only locally. In 1935, the U.S. government created a uniform guide for traffic lights (because different methods of moving along cars and people, like a horn that recognized sound and led to cars honking to change the red, had failed). Potts’ invention became a fairly common thing around the country (and the world, although there are different systems around the world).

The next issue for cities and societies was traffic light timing; there’s a good read on this as it’s done in Orem, Utah here (fun fact: Utah is the only state in the union where every city uses the same traffic light timing system) and another good read (more broadly) here from NPR. (That one focuses on Washington, DC.) Here’s a look at “smart signals” in Seattle that’s pretty interesting:

And get this, from the ITS (Intelligent Transportation Systems) initiative at the University of Minnesota:

SMART Signal (Systematic Monitoring of Arterial Road Traffic Signals) simultaneously collects event-based high-resolution traffic data from multiple intersections and generates real-time signal performance measures, including arterial travel time, number of stops, queue length, intersection delay, and level of service.

Damn. We haven’t even had traffic lights for 100 years yet (a blip in the cosmos) and we’re already at this point. Kinda nuts, but also kinda logical — if ‘big data’ is going to evolve so that we can track anything and everything, why not have data on the essential logistics of how we move around where we live and work?

Now here’s the kicker: Audi is testing a system whereby you’d never hit another red in your life, potentially. It’s linked into the traffic light system of the city you’re in, and here’s how it works:

Information from the traffic light systems is transmitted to the car and shown on the dashboard – or eventually on a heads up display.

When combined with the motion sensors and speed information from the car, drivers can be told exactly how to avoid stopping at red lights.

It shows the driver the speed to select in order to reach the next traffic light during a green phase.

Acoustic signals also warn the driver in advance of red lights.

It’s being tested in Germany and Italy, and Audi set up something in Vegas for the CES show. Here’s the full keynote where they address it:

And here’s some condensed highlights:

The next big thing here could be “virtual traffic lights,” being tested at Carnegie Mellon. Here’s how it works and some of the perceived benefits:

The basic world of Virtual Traffic Lights operates like this: as you approach an intersection, your car transmits data, such as location and speed, to other nearby cars. The virtual system processes this information for all the cars in the area, with the help of a lead car that changes every cycle, and determines your individual traffic signal. Instead of seeing a red or green light hanging in the intersection, you see it on your windshield and stop or go accordingly.

The first advantage to Virtual Traffic Lights is that every intersection with a car now automatically has a traffic light. That may not seem like much, but fewer intersections are equipped with signals than many people realize. In New York City, for instance, only about 24 percent of intersections have a four-way signal. As traffic lights become ubiquitous, road safety should dramatically improve.

The second benefit is a much better traffic flow. The algorithm that governs the virtual system can be written for total efficiency. If the system recognizes that no cars are coming from another direction, it can extend a green signal indefinitely. Likewise, at heavy intersections, it can give preference to the longest line of cars. Using similar technology to Google’s driverless car, the system can also recognize the presence of pedestrians and bicyclists, and orchestrate traffic to suit their needs.

This is a cool idea, but I kinda fear that humanity is too stupid on the whole to make it work contextually. I can think of about 10 people, pretty close to me, who would not really know how to follow such a system. It’s an interesting idea, though.

Finally, here’s something that’s kinda interesting — a look inside the LA Traffic Control center with CNN Money. LA is pretty much synonymous with traffic, at least on the U.S. side (although DC has the worst traffic, purportedly), so how they route cars is pretty cool:

Ted Bauer

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