WASHINGTON - Texting, e-mailing, or chatting on a cellphone while driving is simply too dangerous to be allowed, federal safety investigators declared Tuesday, urging all states to impose total bans except for emergencies.

Inspired by recent deadly crashes - including one in which a teenager sent or received 11 text messages in 11 minutes before an accident - the recommendation would apply even to hands-free devices, a much stricter rule than any state law.

The unanimous recommendation by the five-member National Transportation Safety Board would make an exception for devices deemed to aid driver safety, such as GPS systems.

A group representing state highway safety offices called the recommendation "a game-changer."

"States aren't ready to support a total ban yet, but this may start the discussion," said Jonathan Adkins, spokesman for the Governors Highway Safety Association.

NTSB chair Deborah Hersman acknowledged that the recommendation would be unpopular with many people. "We're not here to win a popularity contest," she said. "No e-mail, no text, no update, no call is worth a human life."

While the NTSB does not have the power to impose restrictions, its recommendations carry significant weight with federal regulators and lawmakers. Another recommendation issued Tuesday urges states to aggressively enforce current bans on text messaging and the use of cellphones and other portable electronic devices while driving.

Currently, 35 states and the District of Columbia ban texting while driving, while nine states and D.C. bar handheld cellphone use. Thirty states ban all cellphone use for beginning drivers. But enforcement is generally not a high priority, and no states ban the use of hands-free devices for all drivers. A total cellphone ban would be the hardest to accept for many people.

The immediate impetus for the recommendation of state bans was a deadly highway pileup near Gray Summit, Mo., last year in which a 19-year-old pickup driver sent and received 11 texts in 11 minutes just before the accident.

NTSB investigators said they were seeing increasing texting, cellphone calls, and other distracting behavior by drivers in accidents involving all kinds of transportation. It has become routine to immediately request the preservation of cellphone and texting records when an investigation is begun.

In the last few years, the board has investigated the fatal accident on the Delaware River in Philadelphia in which a tugboat pilot was talking on his cellphone and using a laptop computer, and a Northwest Airlines flight that sped more than 100 miles past its destination because both pilots were working on laptops.