Vivian Lay

We're looking at the system behind them, meeting the people who decide when they flip from one color to another, and trying to answer the question on every LA driver's mind.

Why is this red light so damn long?

The roots of LA's modern traffic system go back to 1984, when the city was preparing to host the Olympic Games.

LA was expecting more than a million visitors and thousands of athletes.

Traffic in LA was bad, and all these people would be flooding into a city that was already pretty maxed out.

City leaders were worried that athletes and spectators wouldn't be able to make it to their events.

At this time, all of the traffic lights in LA operated independently from each other.

Each one had a timing mechanism that would flip the light from green to yellow to red on a regular cadence.

If a traffic light broke, or if an intersection got extra congested, engineers would likely find out about it from angry phone calls.

And then someone from the city would have to drive out to that intersection to manually reprogram the timing mechanism of the traffic light.

In the process, they would often get stuck in the same congestion they were trying to fix.

But the Olympics gave city engineers the motivation and the funding to try something new.

With the games looming, a transportation official named Ed Rowe assembled a small team and they started tinkering.

And what they came up with was a network that connected 118 traffic lights around the L.A.

Coliseum into a single system.

For the first time, instead of sending someone out to every congested intersection, engineers could see what was happening across a whole area and then adjust signal timing remotely in real time.

The system went online just before the game started.

It was an experiment and it worked.

This is Salida Reynolds.

She's the chief innovation officer at LA Metro.