It's one of those things where it's not ideal, but it's the only way to prevent legal liability. Basically if the AI acts in accordance to the law governing such behavior then the manufacturers are not at fault. Else you'll have different vehicle manufacturers doing what they believe is right (think of all the debate over the "trolley" problem), and each case will have to go through the courts.
There are all sorts of subtle ways you need to "break the law" while driving though. Right now, one sees tons of delivery vehicles pulled over to make deliveries and you have to carefully go over the double yellow line in the middle to get around.
