Why is my bus sliding?


Video demonstrating that I cant get iTween Path to work for me. I am simply trying to get the bus to drive along the road!
WHAT IS THE BEST WAY OF DOING THIS??? Its only a cut-scene, no interactivity…! !! Using the normal animation screen results in the bus nose diving thru the geometry. Using iTween I thought I would be able to “drag” the bus around the road… like from a sphere attached to the path, that is connected by a hinge-joint.. but that doesn’t work.. well its SORT of does.. but…