Also referred to as an autopilot or autodrive car, the driverless car is currently only available through science-fiction, but research in the real world is slowly progressing towards the unveiling of a car that will initially be able to navigate on large highways like the U.S. Interstate system, and with later advances progress to being able to navigate through surface roads, and(in theory) off-road terrain as well.
Once successfully implemented, driverless technology will reduce if not eliminate the need to concentrate for up to hours at a time on the road and traffic, reduce car accidents from one of the leading killers of the industrial world to a rare mechanical failure, decrease travel times by removing the need for human traffic controls and speed limits, and allow passengers to spend their time working or relaxing, increasing both leisure time and productivity.
It will also affect the lives of people who don't use the cars. The technology will help economies with more efficient and reliable transportation. For example, there may be "robot delivery" trucks that are dispatched or run circuits round the clock by independent companies to pick up and deliver goods - a local resturant, for example, could take orders over phone or Internet, make the orders, and then pack and ship them on a truck that makes runs within the neighborhood on an hourly or half-hourly basis.
People who turn their cars to destructive purposes(criminals, the angry, suicidal...) will be less able to engage in the kind of behavior with a driverless car. Even assuming a manual mode exists, safety measures will be around to hit the brakes in situations that look lethal, and people who need the protection will be able to order cars that practice defensive driving and can aid them in a combat situation.