If by self driving you mean driving in a single lane on a highway, then sure, a lot of cars have "automated cruise control" with "lane keeping assists" and "collision avoidance".

But if you mean truly driverless cars on public roads, with noone in the driver seat, then sorry, driving isn't just riding in a lane and reading a handful of road signs. It includes responding to anything in your environment. For example, if you see a ball bounce in front of your car, you will instinctively slow down since there might be a kid running after the ball. A driverless car making that inference? No chance.