What happens if you hit a car abandoned on the freeway?

You have had an accident in which you hit another vehicle, one that was not moving. This is typically interpreted to mean that you were At Fault and responsible for the damages. Fortunately, the owners of the car that was abandoned are not likely to care, but if they discover it, they may try and collect money for the loss to their vehicle. If there is no way of tracing the owner, or proving ownership, the authorities are not likely to cite them for parking illegally, though they may try. If it was simply parked there because of a mechanical failure while the owner/driver went for help or to obtain a tow truck, etc., they may be ticketed and help partially responsible, but it isn't likely.