Weird collision behavior when importing custom road model

My game is a car racing game. When I use the default racetrack from jmonkey, everything works fine. But when I import my own road model, the cars suddenly slip after hitting the road even though they are not moving yet.

I even tried using a simple cube from Maya to test if the model was at fault. But the same things happen, and there’s this weird vertical collision box.

With “slip” do you mean it goes through your model?

Did you try using a box Geometry built by code?

It’s okay now. I was using .fbx before, but when I imported the model with .obj, it worked.
But now the model has no texture applied. How do I fix this?

Just take a look on export options…i mean especially axes conversion, sometimes y and z are inverted.
For the texture, you have to export the material too, or recreate a new one in jme and apply it to your geometry… .obj don’t embed texture, or animations.

That did the trick. Thanks!