Cars are increasingly equipped with technology to keep drivers connected while on the road, but a new study says it can take 27 seconds for a driver using a voice-activated entertainment system to regain full alertness after making a command from behind the wheel. That means a car going 25 mph can travel the length of three football fields before a driver’s brain fully recovers from the act of dialing a phone number or changing music using increasingly popular in-car entertainment systems.

That’s according to new research from the AAA Foundation for Traffic Safety, which concludes that hands-free technologies used by almost a third of D.C. drivers can create mental distractions even if drivers have their hands on the wheel and eyes on the road.

“You’ve shifted your attention to interacting with the device, you stop scanning, you don’t anticipate hazards, you don’t notice things that are in your way,” said David Strayer, one of two University of Utah professors who conducted the study. “It’s kind of comparable to trying to balance your checkbook as you’re driving down the road. No one would do that.”

Researchers looked at a variety of hands-free technologies, including systems equipped in 10 vehicles for model year 2015 and smartphones running Google Now, Apple Siri and Microsoft Cortana. The smartphone technology is widely available, but statistics show that many drivers are jumping on board with the latest in-car entertainment features.

In the District, 29 percent of survey respondents said they have used voice-activated technology while driving during the past six months. Among the 573 adult drivers surveyed, nearly seven out of 10 thought their brain was distracted for only up to 10 seconds when completing an in-vehicle task, such as dialing a phone number or changing a radio station. But 88 percent said they think other drivers are “very distracted or somewhat distracted” when using a device to talk or text.

David Strayer administers a demanding cognitive test that was used in a driving simulator to demonstrate the potential distraction effect of using a hands-free device while driving. (AAA Foundation for Traffic Safety/YouTube)

“We exaggerate our ability to handle it, and we loathe it when we think about other people doing the same thing on the road,” said John B. Townsend II, a spokesman for AAA Mid-Atlantic. “We think we are the exception on the road.”

The study rated the distractions created by the different devices on a scale of 1 to 5. The worst-performing model in the bunch: the 2015 Mazda 6, which scored a cognitive distraction rating of 4.6 out of 5 — almost a full point higher than the next worst systems (the Hyundai Sonata and Chrysler 200c). The best scoring system was found in the Chevrolet Equinox, which scored a 2.4. For context, a driver focused completely on the road scores a 1, while listening to the radio scores about a 1.2, Strayer says. Test subjects solving math problems while memorizing a set of words in a simulated driving environment were operating under conditions similar to a 5.

“First and foremost, the driver’s primary job is to focus full attention on the job at-hand: driving,” Mazda spokesman Jeremy Barnes said in a statement. “Our newest and most advanced system, known as Mazda Connect and seen in the heavily revised 2016 Mazda6 and all of our 2016 lineup, incorporates lessons learned from the previous-generation system that AAA tested. Given the relentless pace of technology advancement, we’re always looking for new ways to make that interface between user and machine smoother and more intuitive.”

The problem with in-vehicle systems, Strayer said, can lie in their user interfaces.

“Some of these systems, they haven’t been really well engineered and thought through,” he said, recalling how one device asked if drivers wanted to make an international call after they had already dialed a domestic number. “People may have an assumption that if it’s in a car it must have been fully tested and really good.”

Strayer says the study’s findings may mean that drivers who think it is safer to send a text when stopped at a red light or a stop sign are mistaken.

“If you have some sort of strategy of only texting at lights, for example, you’re still distracted,” Strayer said. “Those kinds of activities just don’t really belong behind the wheel of a car at this point.”

Even the least distracting systems can leave drivers impaired for more than 15 seconds after completing a task, the study says. The distractions created by device use could limit drivers’ ability to spot hazards ahead of them and make necessary adjustments, said Peter Kissinger, president and chief executive of the AAA Foundation for Traffic Safety, in a news release.

“The lasting effects of mental distraction pose a hidden and pervasive danger that would likely come as a surprise to most drivers,” he said. “The results indicate that motorists could miss stop signs, pedestrians and other vehicles while the mind is readjusting to the task of driving.”

Strayer said the stress the drivers operate under today can be similar to that experienced by fighter pilots. The studies conducted on pilots in the 1970s, he said, mirror some of the findings of today’s drivers.

“What we’re seeing in the car is something that earlier researchers who were looking at pilot distraction were also seeing,” he said. “Just because you’re in the car and it’s possible to do, doesn’t mean you should do it.”