Distracted driving is becoming a scourge on American roads, but the federal agency charged with keeping motorists safe is in a poor position to address the problem, said one of the agency's top attorneys at the Connected Car Expo in Los Angeles.

Kevin Vincent, chief counsel for the National Highway Traffic Safety Administration told the crowd that the current structure of government oversight is antiquated and hinders the agency's ability to make new rules.

"There are limitations on what NHTSA can do," he said Tuesday during a panel discussion on distracted driving and connected cars at the Los Angeles Auto Show.

NHTSA is in charge of regulating the auto industry. The Federal Communications Commission regulates cell phones. As cell phones and automobiles have become more intertwined, having separate agencies covering those industries is just one of the many complexities the government faces in attempting to curb the distracted-driving problem. Another nuance: Cell phones are only part of the problem.

At any given daylight moment, 660,000 motorists are using their cell phones while driving, according to the agency. That number drops at night, but it's alarming. Drivers are using their phones to talk, text, even shop on Amazon, says Nielsen, which researched which apps people frequently use while driving.

Distraction-related traffic accidents killed 3,328 people in 2012, according to data released last week. That accounts for approximately 10 percent of all traffic fatalities. The number of people injured in distraction-related accidents climbed 9 percent last year to 421,000 Americans, according to NHTSA.

For now, NHTSA's policy on cell phones echoes Nancy Reagan's anti-drug campaign from the 1980s: Just say no.

Earlier this year, the agency launched a campaign to discourage motorists from using their handheld devices while driving. It also issued recommendations to car manufacturers telling them to avoid developing interfaces, like touchscreens, that distract drivers for more than two seconds at a time. But those suggestions aren't enforceable. Automakers can voluntarily comply, or ignore them.

That's how the auto industry would like to keep the federal government's involvement.

"It has to be voluntary, because the pace of technology is moving faster than regulators can address," said Mitch Bainwol, CEO of the Alliance for Auto Manufacturers. "I'm not sure the government is structured to deal with high-pace technical reality."

He said regulations can have unintended consequences. In 2006, for example, automakers agreed to lock out changes to navigation while cars were in motion. Stripped of that ability, drivers returned to the more precarious act of simply using their cell phones.

"The whole act of picking up a phone and manipulating it with your hand is very problematic," said Bruce Mehler, a research scientist at MIT who has finished a yet-to-be-released study on the mix of cell phones and drivers that yielded some anticipated results. "To the extent we can integrate it into the vehicle so you are not tempted to pick up that device, that is an important and attractive goal for us."

The phone may be a big part of the problem, but it's not the only area of concern, Mehler's study found. Drivers themselves display concerning behavior.

Even when they're not actually talking on their phones, motorists who frequently do use their phone behind the wheel are prone to more aggressive driving behavior, including speeding and lane changes than motorists who rarely use their handheld devices, MIT found.

"These same individuals are then more likely to spend excessive time with the radio, doing makeup and doing other things in the car," Mehler said. "It's not just the interface."

Pete Bigelow is an associate editor at AOL Autos. He can be reached via email at peter.bigelow@teamaol.com and followed on Twitter @PeterCBigelow.