A number of different Water and Frost Protection Systems (W&FPS), or so called inner linings, have during the years been introduced and tested in Norwegian road tunnels. At present a limited number of such systems have been approved by the Norwegian Public Roads Administration (NPRA). These systems will all be described in brief. A system based on pre-cast concrete segments will be described in details, including the installation procedure. Experience and limitations associated with this system will also be discussed. A basic design concept for using an inner lining as water and frost protection is that there is no interaction between the inner lining and the rock support. The rock support practise in Norwegian traffic tunnels will also be briefly described in this paper. Sprayed concrete and rock bolts are the main support measures. In-situ cast in place concrete lining is only used locally to solve severe stability problems.