Like I thought, the riadkill is still present in the N64 porting, but I don't know yet if is complete.
http://datacrystal.romhacking.net/wiki/Cruis'n_USA_(Nintendo_64):Notes
For now you have to set a code to see how it works, without the right 3D models and textures unfortunately. Someone know if there is a way to found the 3D models in the game without have to read them from the memory dump? Should be useless otherwise if the 3D models aren't yet loaded in ram... Does exists then a tool to explore the 3D models into a rom? Cruis'n USA is uncompressed...