I always wanted to archieve that effect. I got some documentation but i didn't get it.
Also, the road is bunch of sprites or drawings on the graphic screen?
I am roughly following along with the outrun-ish code from the code incomplete website. I still have lots of bugs and lost half my frame rate so far.
I may try making everything sprites later, right now it is a bunch of quads made from triangles. In the original arcades they would change offsets on each line as the screen was drawn which isn't really do-able in SmileBasic.