LOS ANGELES (AP/CBSLA.com) — Just because you can talk to your car doesn’t mean you should.

Two new studies have found that voice-activated smartphones and dashboard infotainment systems may be making the distracted-driving problem worse instead of better.

The systems let drivers do things like tune the radio, send a text message, or make a phone call while keeping their eyes on the road and their hands on the wheel, but many of these systems are so error-prone or complex that they require more concentration from drivers rather than less, according to studies released Tuesday by the AAA Foundation for Traffic Safety and the University of Utah.

KNX 1070’s Jon Baird reports two studies – one focused on infotainment systems in the most common auto brands and the other on the Apple iPhone’s Siri voice system – showed just how distracted drivers are becoming due to their gadgets.

The voice-activated systems were graded on a distraction scale of 1 to 5, with 1 representing no distraction and 5 comparable to doing complex math problems and word memorization.

Apple’s Siri received the worst rating, 4.14. Twice test drivers using Siri in a driving simulator rear-ended another car.

Chevrolet’s MyLink received the worst rating, 3.7, among the infotainment systems. Infotainment systems from three other automakers – Mercedes, Ford and Chrysler – also were rated more distracting for drivers than simply talking on a hand-held cellphone.

The systems were tested by 162 university students and other volunteers in three settings: a laboratory, a driving simulator and in cars while driving through a Salt Lake City neighborhood. Researchers say those with the worst ratings made errors even though drivers’ voice commands were clear and distinct.

For example, an infotainment system might recognize a command to change a radio station to “103.5 FM,” but not “FM 103.5” or simply “103.5”.

“Even as you speak what you want it to write, as soon as it writes it, you always wanna double-check because it doesn’t always get it right,” said one driver. “And that’s when you plow into a pole.”

Apple noted in a statement that researchers didn’t use the company’s CarPlay or Siri Eyes Free, which are designed for use in cars.

However, David Strayer, the University of Utah psychology professor who led the two studies, said researchers consulted with Apple before beginning the study. The study used an iOS 7 version of Siri that was tweaked to be nearly identical to the iOS 8 version, which was just recently released, he said.

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