PHOENIX -- Have a text message you've just GOT to get to a friend right now?

State lawmakers want you to wait, at least if you're behind the wheel.

Legislation approved Wednesday by a Senate panel would make it illegal to use a cell phone while operating a motor vehicle. Violators would have to pay $50 if caught.

But the penalty would go up to $200 if the errant motorist were involved in an accident.

In its current form, SB 1443 covers all use of cell phones unless the person has a hands-free device, whether a Bluetooth-enabled earpiece or a hard-wired headset.

But Sen. Al Melvin, R-Tucson, who crafted the measure, said he's likely to narrow the scope when the measure gets to the full Senate. He said that, in his mind, that's the bigger problem.

"It seems hardly a week goes by that we don't hear of a horrendous accident in the United States involving not just one but multiple loss of life, mostly because of the driver texting,'' he said. "That's the sole motivation here, is to save lives.''

Sen. Leah Landrum Taylor, D-Phoenix, said she appreciates the concerns about safety.

"I certainly can't agree with texting or reading or all kinds of things that people do while they're supposed to be driving,'' she said. But she questioned whether the measure is crafted too broadly.

For example, she questioned whether the law should apply if someone is sitting at a stop light or parked. There is case law in Arizona that says anyone behind the wheel of a vehicle that is running is considered operating a motor vehicle, whether the car or truck is moving or not.

Sen. Linda Gray, R-Glendale, said a law that bans texting but allows talking on a cell phone could be difficult to enforce.

She noted that would keep it legal to dial a phone.

But that requires pushing the same buttons as texting. And the difference would not be obvious to someone outside the vehicle.

"Would I get a ticket for that?'' she asked.

Melvin's bill, which cleared the Senate Committee on Public Safety and Human Services on a 4-2 vote, does include some exceptions, such as for police officers and the drivers of other authorized emergency vehicles while performing official duties.

Some of the other exceptions, however, raised concerns.

One, for example, would permit public transit personnel to send text messages. Gray recalled an accident last year involving the driver of a commuter train in Los Angeles who had been texting around the time of the crash.

She also questioned the advisability of an exemption for those with commercial driver licenses, people who might be driving 80,000 tractor-trailer rigs.