How to create Transfagarasan server with downhill layout

[nunoClara]

Hi guys.
Transfagarasan is one on my favarite roads in AC and me and my friend can't create a server with the downhill layout.We have to do the uphill and then do it on reverse(with .ai files renamed).We would like to start in that parking lot with the helicopter.Does anyone know how to do it?
Thanks