When two ambulances, sirens blaring, get to an intersection at the same time, which one gets to go first? It’s a scenario that can result in accidents and add precious seconds to response time. Now Maricopa County, together with federal and state traffic planners, is testing new technology to transmit real-time road information to vehicles.

As cars get smarter, so do transportation departments.

And if the National Highway Traffic Safety Administration passes a proposed rule, all automakers will have to include vehicle-to-vehicle communication in every new car.

(Photo by Casey Kuhn - KJZZ)

A vehicle with connected car technology.

“It happens so fast that I can’t get the little steps that are occurring for you guys to visualize,” said Larry Head, Director of the University of Arizona Transportation Institute.

Head walks through a demo of the project in Anthem. He directs UA institute and works with Maricopa County. They’ve developed a system to connect traffic signals and cars.

“So the idea is the cars are talking to each other, they can also talk to the infrastructure," Head said. "They can talk to the traffic signals and say ‘here I am!’ and the traffic signals can say ‘oh I see you’re there, let me give you a green light and let you go through.’”

It gives the car a map of the lane lines.

“This is a high definition map, this isn’t what you get from Google.”

And it’s like a special dialect — car talk, if you will.

“I like to call it the language of the road," Head said. "And it’s going to begin speaking to you and it’s going to be an active part of what you get in your vehicle. Hopefully to keep drivers more engaged and reduce accidents.”

So how exactly does that work?

It’s sort of like super-fast WiFi — imagine a router on top of a traffic signal, sending information like crash sites or school zones through wavelengths. The car would have a sensor, like a laptop taking that info and telling the driver what to expect.

(Photo by Casey Kuhn - KJZZ)

The inner workings of a connected car traffic signal box.

For now, the Maricopa County Department of Transportation is testing it on emergency vehicles and this is only one of seven in the country.

Faisal Saleem is the SMARTDrive program manager at MCDOT.

“Definitely, the systems improve the safety of the responders," Saleem said. "And the second goal is to improve the response time. In an emergency response, every second matters.”

He said when the emergency vehicles have the tech, the traffic signal will change its pattern to allow one priority if there are two at an intersection.

“This is the future we are looking forward to because this is just one application," Saleem said. "USDOT [United States Department of Transportation] has more than 50 applications.”

For MCDOT traffic planners like Denise Lacey, this future tech means a shift in how congestion is typically managed on the roadways.

“We have to change our mode of thinking a little tiny bit to determine how we’ll prepare for that in the future and there’s a lot of studies going on for that nationwide,” Lacey said.

As the county uses this information to find where cars are at a given time, the inevitable question comes up: how is my car’s data going to be used?

(Photo by Casey Kuhn - KJZZ)

UA professor Larry Head works with MCDOT on the connected car technology.

 Head said the system has been designed to make it impossible to keep and track data like that.

“So every five minutes the vehicle changes its ID. And there’s nothing in the message that goes out over the wave that is identifiable back to the vehicle,” he said.

And the next question — what if the system’s hacked?

“What we don’t want are fake cars out there," Head said. "Somebody driving down the road saying 'I’m gonna tell everybody I’m ten cars' and clearing the road so they can get through. We need to know those are fake cars.”

Head said it’s a huge concern and the program is developing countermeasures.

So, did the demo work?

“Now the signal just changed to red — what happened?”

In the car, Head can see what map they are on, and that another emergency vehicle is approaching.

“We want to minimize the delay to the transit vehicle in an intelligent way,” Head said.

It’s sort of stop-and-go, with a delay to the other vehicle because there are cars on the road. It's not a test track, this is being tested on busy Anthem streets.

“There we got our green and we get to go,” Head said.

So they’re still working out the bugs testing the new technology. But the goal is starting in 2021, every new car will have sensors and local traffic signals that could be talking to a car on a road near you.

(Animation courtesy of MCDOT)