Shut down the engine when someone is still driving? That's not just inconvenient, that's suicidal. What if you're not able to get back to a place with cell cove

Shut down the engine when someone is still driving? That's not just inconvenient, that's suicidal. What if you're not able to get back to a place with cell coverage in time? Is the car just going to stop in the middle of the highway or the middle of a tunnel?