U.S. highway deaths continued to rise sharply in 2016, prompting a leading safety group to recommend that all cell-phone use be banned in vehicles.

It was the second year in a row that the U.S. saw a spike in highway fatalities, according to the estimates of the National Safety Council. The preliminary estimate for 2016 is 40,200 deaths, up 6 percent from the previous year. Over two years, the fatality count has risen 14 percent—the biggest two-year increase since 1964.

"Our complacency is killing us," said Deborah Hersman, president and CEO of the nonprofit National Safety Council, a public-health group based in suburban Chicago. "Forty-thousand deaths a year can’t be our new normal. It starts with strong laws and personal accountability and responsibility.’’

One of the most important actions is putting cell phones away before driving, Hersman said.

Driver distraction may be causing more than 3,000 fatalities per year, according to the National Highway Traffic Safety Administration. The real number is probably even higher, because police reports don’t always record distraction as a factor in a crash.

States should ban all cell-phone use, not just handheld devices, because research shows that it’s the act of thinking about the conversation, not dialing or holding the phone, that causes driver distraction, the safety council said.

Beyond that, the industry could do more to offer devices that can be put into "driver mode," locking out particularly distracting functions, Hersman said.

"One of the issues we have with phones is people are addicted to them,’’ Hersman said. "It’s very hard to separate people from these devices in this 24/7 responsive society."

Last November, NHTSA issued a set of proposed guidelines for makers of portable electronic devices to reduce the potential for distraction. They included ways to pair the devices to a car’s infotainment system and the addition of a driver’s mode.

Beyond distracted driving, the National Safety Council is recommending mandating ignition interlocks for drivers convicted of a single alcohol-related offense. The group is urging states to rethink speed limits of 70 mph or more, and increase use of speed cameras in cities. It also would like to see tougher seat-belt laws applied to every seating position in the car.

"The same things that have been killing us for decades are still killing us," Hersman said. "We know what to do. We’re just not doing it."