GOOD

Can the Physics of 'Green Waves' Help Los Angeles Perfect Its Synchronized Traffic Lights?

Can the Physics of “Green Waves” Help Los Angeles Perfect Its Synchronized Traffic Lights?

\n
If you drive in a major city, you probably experience it every once in a while: Traffic isn’t too heavy, you’re driving at a comfortable speed, and you just happen to hit a series of green lights. You blissfully cruise through several intersections without stopping. It’s a nice feeling when it happens—but it’s also makes for a more efficient and cleaner city. Smoothly flowing traffic means less pollution, less congestion, and less time wasted.
As you might imagine, cities try to engineer this phenomenon by synchronizing traffic lights. Synchronization involves calculating the time it takes to get from one intersection to another, based on the speed limit or likely speed of traffic, and then timing the lights at those intersections so that as a driver approaches each intersection, the light will turn green in time for traffic to proceed without stopping.
New York, San Francisco, and many other cities have synchronized traffic lights in limited areas. But this year, Los Angeles completed the largest traffic light synchronization project in the world. The city synchronized 4,398 traffic lights across 469 square miles. The project was first launched in advance of the 1984 Olympic Games. It was mothballed for a little while, but revived by Mayor Villaraigosa in 2005, and finally completed in February.
The new system “increases travel speed by 16% and reduces travel time by 12%,” says Jaime de la Vega, General Manager of the Los Angeles Department of Transportation. That’s not bad, but it’s lower than the city predicted. And a new report from the Associated Press suggests that the results have not matched the scale of the project. One veteran taxi driver’s take: "To be honest with you, I haven't felt it yet."
So the project has been good, but maybe not great.
Science to the rescue. Physicist Boris Kerner at the University of Duisburg-Essen has been studying the dynamics of “green waves” of smoothly flowing traffic. Using various models of traffic flow, he explored how different conditions can cause a “green wave” to break down. These breakdowns are generally due to an over-saturation of traffic or to a disturbance (as when a car turns into a green wave and disrupts its flow). He is, apparently, the first to rigorously study this phenomenon.
And this is especially promising for Los Angeles precisely because the city has linked a large grid of streets together in a system that can be studied and adjusted in real time. If discoveries like Kerner’s can provide solutions to green wave breakdown, it’s possible that Los Angeles could actually implement them and experiment with them.
Join us for our Fix Your Street Challenge. Click here to say you'll Do It and enter our GOOD Maker Challenge here.\n


\n
Photo via (cc) Flickr user flrnt
Articles
Screenshot via Sweden.se/Twitter (left) Wikimedia Commons (right)

Greta Thunberg has been dubbed the "Joan of Arc of climate change" for good reason. The 16-year-old activist embodies the courage and conviction of the unlikely underdog heroine, as well as the seemingly innate ability to lead a movement.

Thunberg has dedicated her young life to waking up the world to the climate crisis we face and cutting the crap that gets in the way of fixing it. Her speeches are a unique blend of calm rationality and no-holds-barred bluntness. She speaks truth to power, dispassionately and unflinchingly, and it is glorious.

Keep Reading Show less
The Planet
Ottawa Humane Society / Flickr

The Trump Administration won't be remembered for being kind to animals.

In 2018, it launched a new effort to reinstate cruel hunting practices in Alaska that had been outlawed under Obama. Hunters will be able to shoot hibernating bear cubs, murder wolf and coyote cubs while in their dens, and use dogs to hunt black bears.

Efforts to end animal cruelty by the USDA have been curtailed as well. In 2016, under the Obama Administration, the USDA issued 4,944 animal welfare citations, in two years the numbers dropped to just 1,716.

Keep Reading Show less
Science

The disappearance of 40-year-old mortgage broker William Earl Moldt remained a mystery for 22 years because the technology used to find him hadn't been developed yet.

Moldt was reported missing on November 8, 1997. He had left a nightclub around 11 p.m. where he had been drinking. He wasn't known as a heavy drinker and witnesses at the bar said he didn't seem intoxicated when he left.

Keep Reading Show less
Communities
via Real Time with Bill Maher / YouTube and The Late Late Show with James Corden / YouTube

A controversial editorial on America's obesity epidemic and healthcare by comedian Bill Maher on his HBO show "Real Time" inspired a thoughtful, and funny, response by James Cordon. It also made for a great debate about healthcare that Americans are avoiding.

At the end of the September 6th episode of "Real Time, " Maher turned to the camera for his usual editorial and discussed how obesity is a huge part of the healthcare debate that no one is having.

"At Next Thursday's debate, one of the candidates has to say, 'The problem with our healthcare system is Americans eat shit and too much of it.' All the candidates will mention their health plans but no one will bring up the key factor: the citizens don't lift a finger to help," Maher said sternly.

Keep Reading Show less
Politics
via Gage Skidmore

The common stereotypes about liberals and conservatives are that liberals are bleeding hearts and conservatives are cold-hearted.

It makes sense, conservatives want limited government and to cut social programs that help the more vulnerable members of society. Whereas liberals don't mind paying a few more dollars in taxes to help the unfortunate.

A recent study out of Belgium scientifically supports the notion that people who scored lower on emotional ability tests tend to have right-wing and racist views.

Keep Reading Show less
Politics