Increase the testing requirements for new drivers to make it harder to get a license, for starters. Or make it easier to suspend people's licenses for acts of unsafe driving.

America has extremely low requirements to get licensed as a driver; this is intentional. We wanted everyone out of public transit and into cars. In other countries it's far more difficult to get licensed to drive, you're expected to have more skills. Hell, most drivers in Europe drive stick because you're required to test on a manual transmission.