In the US, the insurance company or surviving family of the pedestrian can file a civil claim against the insurance company or estate of the driver.

Wrongful death suits can be brought sickly against an estate

Accountability? That's different than punishment.

The driver cannot be held accountable because they are dead. They are not going to be able to learn from their mistakes.

Depending on where you are, the driver would have liability insurance on their car. The victims family can sue for various expenses and damage depending on the law where you are.

This is the kind of question that gets you put on certain lists