We have the technology to produce cell phones that would be inoperable in a moving vehicle, at least in the driver's seat. We also could make autos that would make cell phones inoperable while the vehicle is in motion. Of course these units would never be sold.
Laws making it illegal to operate a vehicle while distracted is almost impossible to enforce - unless, of course, it is after an accident caused by a distracted driver.
Life must have been terrible before cell phones when you had to leave your car to get to a phone. Then, of course, no one could bother you while you were driving.