From another article,
"Humphreys told the FCC he used the jammer to keep people from talking on their cellphones while driving. Talking on a cellphone while driving is legal in Florida, even without a hands-free kit, though texting while driving is banned. Using a cellphone jammer is illegal for everyone but federal law enforcement, regardless of intent, according to the FCC."
A moving jammer, that doesn't center on the phone caller seems more disruptive rather than less. If your call drops while in motion you're going to retry. This is more helpful to prevent calls in the first place - but even that means they go for their phone. It seems to me the talking isn't the distraction AS much as the dialing.