can not counting cars number correctly

hello , first thanks for your good library .
i try to count cars and also i want to put number of each car above the car.
i try to do it but i saw one of car not die and another car keep on its track , so total number always is wrong and number of each car also wrong. i really confused and wast more time on this bug.
please tell me whats the problem? and how i can do that?
another problem happen, when i ShowAB=0 i saw that both A->B and B->A counting that must just one of them counted in vertical or horizontal line, i think its related to before problem that i pointed to.

thanks in advance
i waiting for your help