Motorists in Honolulu will be prohibited beginning Wednesday from driving while holding a cellular phone, and police reminders of the new ordinance indicate they plan to enforce it. That should not cause motorists using a Bluetooth headset or other hands-free phone, which remains legal, to think they are safe from the danger of distraction.

It's about time for such a requirement, inadequate as it might be. More than 40 countries have such a law, along with four states and numerous municipalities. Twelve years have passed since a study published by the New England Journal of Medicine found that the risk of an accident while the driver is on a cell phone quadruples, about the same risk as driving drunk.

Not that a Bluetooth headset is any safer. Nearly eight years have passed since researchers at the University of Utah completed a study finding that hands-free phones are as distracting for motorists as hand-held cell phones.

“;When you're on a call, even if both hands are on the wheel, your head is in the call, and not on your driving,”; says Janet Froetscher, president and CEO of the National Safety Council. “;Unlike the passenger sitting next to you, the person on the other end of the call is oblivious to your driving conditions.”;

Many people question how talking on a cell phone is more distracting than eating, drinking or engaging in other hands-on activity. However, keeping your attention on the road is much easier while handling food or a drink than talking on a cell phone, for the obvious reason that it is less mentally distracting.

The Utah researchers explained that a cell-phone chat diverts the driver's attention “;to an engaging cognitive context other than the one immediately associated with driving,”; which is why a driver talking on the cell-phone appears to other motorists to be in another mind zone.

Eighty percent of crashes are related to driver inattention, and the leading source of such inattention is cell phones, according to a Virginia Tech study. More than 100 million people use cell phones, and an insurance public-opinion poll found that 81 percent of the public admits to talking on a cell phone while driving.

Acting on the issue is obviously risky for politicians, which is why the City Council was slow to act and state legislators continue to look the other way.

The City Council can feel good about enacting the cell-phone ban, but members should realize that this is a first step, equivalent to requiring that safety belts be half-clicked.