Who is at fault when a person is pulling out of a parking spot and going slowly using caution and a car traveling the parking lot collide?

A vehicle traveling in a parking lot has established use of the lane and the right of way. A vehicle in a parking space and backing into the lane must yield to oncoming traffic. Therefore, if a vehicle is backing out of a parking space and pulls into the path of an oncoming vehicle that has already established the lane, the vehicle backing would be at fault for the accident.

However, if the vehicle which established use of the lane had an opportunity to avoid hitting the vehicle backing out of the space and failed to do so, there could be comparative negligence on both vehicles or on the one who had the opportunity to avoid the accident.