The automobile, in American life, has long been a hallmark of freedom. A teenager’s first driver’s license offers freedom from Mom and Dad. A new car and the open road bring the freedom to chase the American dream. But as more technology creeps in to help drivers, so, too, will systems that eavesdrop on and monitor them, necessitated not by convenience but by new safety concerns.

Cameras that recognize facial expressions, sensors that detect heart rates and software that assesses a driver’s state of awareness may seem like superfluous flights of fancy, but they are increasingly viewed as part of an inevitable driving future.

At upstarts like the electric car company Byton and mainstream mainstays like Volvo, car designers are working on facial recognition, drowsy-driver alert systems and other features for keeping track of the people behind the wheel.

The most immediate impetus: concerns about the safe use of driver-assistance options like automatic lane-keeping that still require drivers to pay attention. And when truly autonomous vehicles finally arrive, the consensus among automakers and their suppliers is that new ways will be needed to check on drivers and passengers to make sure they are safe inside.