Cell phones have altered the landscape for personal and business communications — on balance, a good thing for society.

But a cell phone's capacity to distract the caller can be destructive, especially when it's combined with operation of a motor vehicle.

Bill 4, the measure now before the City Council, comes much closer to a practical, enforceable regulation of that activity than the previous proposal, which would have barred only the use of the phone's text-message function.

The proposal targets all hand-operated mobile electronic devices, including games, PDAs, cameras, text-messaging devices and pagers. Cell phones or other devices that offer hands-free adapters are allowed while driving.

The revised draft of the bill, due to come up for a second reading before the council in one week, includes several reasonable revisions:

• Callers who dial 911 while driving can present records of the call as an affirmative defense against a citation.

• Emergency responders will be exempt if they are using an mobile electronic device while in the performance and scope of their official duties. The bill defines this class as firefighters, emergency medical service workers, mobile intensive care technicians, civil defense workers, police and federal and state law enforcement officers.

• Also exempt will be drivers using two-way radios in the course of doing their official work. The reasoning is that these communications are limited to specific persons and involve devices that don't require much more operation than a push-button.

Several bills were introduced in the Legislature to extend such a ban statewide, but the only measure still moving is one that applies the restriction only to drivers under 18.

This may seem a rational compromise, but only a temporary one, while the state evaluates the results of a

Honolulu-only ordinance. Minors by far represent the group at highest risk of a crash.

But they are by no means alone in the addiction to electronic devices, so there's no real reason a different standard should apply to adults.

A 2006 study conducted for the National Highway Traffic Safety Administration ranked cell phones as the most common distraction for drivers, and distraction was implicated in 80 percent of all crashes.

Certainly, there are other causes: Most have witnessed people eating and applying makeup behind the wheel.

It's impossible to eliminate poor judgment through legislation, but deterring one common misbehavior would be a step worth taking. In the interest of safety on our roads, Bill 4 should pass.