Lawmakers think it's dangerous to drive one handed. I don't disagree.
But they don't address features of phone calling that are far more risky -- but still required even when using a hands-free device. Such as looking down at the phone to dial someone's number, which can take drivers' eyes off the road for a good long time. And they're driving one-handed while doing it. And likely drifting into the next lane too.
Funny, also, that legislators don't include texting in their laws. I'm sure people are engaged in DWT - Driving While Texting. With both thumbs.
It's not illegal anywhere yet, but lawmakers in a handful of states are certainly looking into it, especially Washington State, which could become the first state to ban DWT. It's probably safer to drive holding a phone to your ear. At least you're watching what's going on in front of you. Not that I'm endorsing it.
In any case, are these laws enforced? I live in Washington, DC, which has a hands-free phone law. I see plenty of people flouting it daily. While turning corners. In big SUV's. Then there are the other people, the red-faced ones screaming at them to get off the !#$*^%!! phone.
It's a problem that needs solving, but we don't seem to be there quite yet.