Interesting problem. How do Google's self-driving cars react to road problems such as bridge-collapses and sinkholes? Scanning for objects and avoiding objects which extend above the road level is obvious, but what about when the road cuts off? These things rarely happen, but it would be terrifying to be in a self-driving car in that moment when the bridge ahead of you collapses and the car continues to drive as if there is nothing wrong.

I actually had a similar thought yesterday when thinking about how the cars would handle object-avoidance. Say a deer hops out in front of the car. The car is constantly aware of its environment for 100+ feet in all directions, so it could tell if there are no cars in a neighboring lane and swerve to miss the deer. But what if there _are_ cars in neighboring lanes and the only available direction is to go onto the shoulder or into the ditch? If the ditch is fairly level with the road, then this could be the safest option. But if the ditch is steep, then it would be more dangerous than simply hitting the brakes and hoping you don't hit the deer too hard.