Most likely anyone would choose to save themself and their mother because they would be disowned by their family and it is also like biting the hand that feeds you. plus the old saying "blood is thicker than water" fraise could be used in a situation like this. So if you choose to save yourself and one other "Mother/Spouse" you would be considered selfish and would have to live with the thought that you had the choice to choose who lives and dies.
I think that I would rather be the one who drives off the cliff even though it is easier said then done.
Unless i had the option of diving out of the car and onto the road.