Intelligent vehicles and highway systems that communicate with drivers and each other to improve safety and traffic flow still have a long way to go before they become a routine part of transportation infrastructure. But its deployment can’t come too soon for a population of motorists who seem to be focused on anything but driving.

Sure, everyone has horror stories of seeing fellow motorists doing everything from shaving and applying makeup to reading newspapers and playing the trumpet at high speeds. And it’s the rare driver who hasn’t dodged another vehicle whose driver had a cellphone pressed against his or her head.

However, a study sponsored by the AAA Foundation for Traffic Safety released this week found that despite the emergence of hands-free phones, GPS units, and devices intended to help drivers stay focused on driving may actually be causing them to lose focus by diverting their attention. These “cognitive distractions” means drivers are slower to recognize and react to cues such as signs, merges, and brake lights.

In other words, though their hands may be on the wheel and their eyes directed forward, drivers’ minds are, at least figuratively, all over the place. And the human brain can handle only so many competing distractions.

Distracted driving, which has been a longstanding crusade for outgoing Transportation Secretary Ray LaHood, is also a factor in an increasing number of traffic crashes—just under 400,000 in 2012 according to data cited in a Washington Post article on the study.

Dozens of states have banned texting while driving, but there are still phones, radios, GPS units, MP3 players, and other technologies being stuffed into vehicles that allow drivers to take their 21st Century toys with them wherever they go—even if it’s into a ditch, a traffic barrier, or—worse yet—another vehicle.

 This has implications for infrastructure, since smart roads and smart cars potentially have the ability to identify and respond to routine cues such as speed and following distance; congestion problems; weather conditions; and the presence of pedestrians, cyclists, obstructions, and oncoming/adjacent vehicles. Fully autonomous vehicles such as Google’s self-driving car also have the potential to create true “hands-free” driving, allowing motorists to multi-task to their heart’s (and brain’s) content.

Many years, tests, and evaluations separate today’s concepts with tomorrow’s rollouts, however, not to mention consideration of what physical changes to road systems (e.g., pavement markings, structures and utilities for overhead/roadside support equipment, etc.) will be needed to complement these technology enhancements. Meanwhile, the gadget ladening of cars and trucks continues. And what’s not built-in, drivers will surely bring along themselves.

Which is fine when these tools are managed effectively and safely. Technology is, after all a wonderful thing, as is the human brain. Problem is, both have their limitations.