On a Monday night in Washington, I easily rolled through an intersection in a new Audi A8. The next traffic light at the end of a block of Pennsylvania Avenue was glowing a steady green. But instead of keeping my foot on the gas, I took it off.
The car told me to do that: This A8’s dashboard reported that the green light would expire before I reached it, then I’d have to wait about 70 seconds. And as forecast, the light turned from green to yellow to red before I would have cleared it.
Nearing other intersections around the District and Northern Virginia, the same display assured me that I would hit the next green, and even told me how fast to drive—usually at the speed limit, but in one case five miles per hour under it.
This vehicular telepathy came from a smart-cities technology that lets traffic lights talk to vehicles. At a minimum, it could lend some tranquility to your drive. At best, it could save fuel and therefore money, and speed everybody’s commute, even for people on the bus.
How traffic lights can talk to a car
The A8 L quattro Audi loaned incorporates what the German carmaker calls Traffic Light Information. Built with Beaverton, Ore.-based Traffic Technology Services,TLI pulls timing data from nearby lights via the car’s AT&T (T) LTE connection and displays that on its dashboard and a heads-up display projected on the windshield.
When launched in the U.S. at the end of 2016, TLI only provided red-light countdowns, but in February Audi added "GLOSA"—a Green Light Optimized Speed Advisory of how fast or slow to drive to meet a green light.
When all this works, it’s like a road superpower. You know the state of a traffic light before you can see it—best case, it will be green for you, worst case you know how long you’ll wait, give or take a few seconds.
(Audi’s system stops counting down with about five seconds to go, a step meant to discourage drag-racing starts.)
Turn-only lanes and signals can confuse this system, though. Its red-light countdown once dropped from about 70 seconds to 7 when the car took a moment to realize I was in a left-turn lane with a separate signal.
But more often, traffic made TLI’s advice not just useless but dangerous: Driving the recommended 35 or 40 mph would have sent the A8 barreling into the back of a bus.
TLI deployments in the District and Virginia also suffered from spotty implementation. I didn’t encounter any intersections online in D.C. Sunday afternoon, and a day later numerous intersections remained offline. In Northern Virginia, I learned that the 1,450-plus signals online did not include such traffic clots as the intersection of Leesburg Pike and International Drive in Tysons Corner.
Audi’s implementation—also online at traffic lights around Dallas; Denver; Gainesville, Fla.;, Houston; Kansas City, Kans.; Las Vegas; Los Angeles; New York; Orlando; Phoenix; Portland, Ore. and San Francisco—raises other speed bumps.
Cost comes first. The cheapest TLI option in Audi’s 2019 lineup is the $37,400-and-up A4. Then you’ll need to pay for the Connect Prime bundle covering this service, which runs $499 for 18 months.
If you don’t need all the other features of Connect Prime, you might prefer to guesstimate traffic-light timing from such indicators as pedestrian countdowns on the opposite crosswalk.
Traffic Technology Services chief marketing officer Kiel Ova said the company has signed other carmakers and expects one to announce support later this year but can’t name any yet. He added that TTS is also open to partnerships with navigation-app developers.
“If somebody comes to us with a use case and their business,” he said, “we’re in the business of selling this information.”
A competing traffic-data firm, Connected Signals, is relying more on apps. Although it lists BMW as a partner, its Enlighten apps for Android and iOS make its stoplight data (available in New York, Phoenix and San Jose, among others) available for free.
Fortunately, Audi, TTS and Connected Signals say their systems don’t keep personal records—meaning they can’t run over your privacy by reporting that you ran a red light.
“Our data is anonymized,” said Connected Signals president David Etherington. “We’ll know that someone ran a red light at that time, but we won’t know that it’s you.”
The payback down the road
In one car at one stoplight, this may not seem like much—as Strategy Analytics associate director Roger Lanctot half-jokingly emailed, it’s “not a lightning-strike, life-saving proposition.”
But the point of this exercise isn’t to help the occasional driver hit 55 green lights in a row; it’s to seed small efficiency gains at scale. In a single car, the logical next step for this technology is to shut off the engine during red lights. Self-driving cars could also use this. And on a bus, dozens of people instead of one or two can benefit—especially when systems like these add signal-priority tools that let buses extend green lights.
Looking down the road, the upside becomes clearer—the potential to, as Lanctot said, “change our notion of driving.”
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