Yes I already have such a system with a menu. But now I am looking for making it more complex. I know everything how I'd do it. I only don't know how i could make the curves. because I thought I'd split one curve up in a couple of small pieces. But I don't know how to calculate the position, pan and such things.

dont try and whip it all together at once.. try and do something small, that will help you understand how it will work. THEN do the actual game.

Look up some AUM tutorials. They are very very helpful.

Sorry but I understand the basics and the things from the AUM. If you look on my Sites then you know that I even have a prototype game with full level-editor and things.
All I wanted to know if someone already has done such a thing with streets and still hase the algorithm for a such calculation.

But as it seems that they don't I will do it myself. Thanks anyway