Maybe the solution is to include "driving with a cellphone" as part of
the driving test.

It would be a simple matter to include a test segment where during
parallel parking the driver would have to answer a number of questions
by phone as the driving instructor further distracted them with babble
while the latest excuse for music was blaring from the radio.

If you did not complete all the tasks within a specified time period
you would fail the test and not receive your license.

This would be much better for all concerned than to fail the real test
and lose your life and take me with you.

TMT