Here's how bilinear parallax works.
You'll need to figure out how many images you want to render or prescale for your depth. That's the easy part, the pieces are drawn from left to right, top to bottom. They're placed like scales on a fish. If you've seen Outrun, then you've seen that the tiles for the road are like round fish scales.
Here's the part where it gets interesting. I don't know if they were using 3D-2D math to calculate the tile placement, or if they were just using an algorithm to calculate angles. I'd say they were using a 3D-2D coordinate system for the tile placement. You'd have to write your own culling routine so that it would render/calculate less and less the closer things got to you since it would fall outside your depth of field.
That works well for strait forward rendering, you'll have to plot the dips and bends in the road manually. You'll also have to write your constraints in terms of how far offroad you can go, as that will also change what falls within your depth of field.
You won't have to work out angles, as the 3D-2D coordinate system will do that for you.
I used to have a tiny 10 line program that performed 3D-2D. It drew wireframe 3D objects using some data statements for the verticies. If I can find it, I'll post it. You can extrapolate what you'd need from that for your 3D-2D coordinate system.
