In 1998 it was decided to use a real-time Global Positioning System when re- opening a high mountain road in Norway after the winter season. Preparations of recording fixed positions along the road started in the summer of 1999 on the trunk road (Route 55) Sognefjell. Installing a GPS recording instrument in a vehicle did an overall recording of the road possible after identifying fixed position marks in the landscape nearby the road, and by using a local positioning transmitter on the fixed mark as a reference. The white roadside marking line was measured every ten meter, and all safety fences, bridges lay-bys and parking areas were recorded on the actual road. All the data were processed and recorded into a map-software designed by the Norwegian Public Road Administration. An accuracy of plus/minus 5cm is possible to obtain when using 5 available satellites combined with data from the reference station to the recording unit bearing the GPS receiver equipment. When the road was to be re-opened after the following winter season, a GPS receiver and a computer containing the recorded road-data were installed in a rotary snow cutter, and also the local reference positioning station was reinstalled and activated. Thus, the local position of the snow cutter was always known. The engineer driving the equipment was continually updated of his position on the road by using a computerised screen map displaying the distance to the edge of the road and any known obstructions recorded from the data entry session. Several snow cutting units operating simultaneously on the actual road can use the same GPS system, and the system can be used regardless the quantity of snow. The benefits of using real-time GPS as hereby described are many. The experiences from the re-opening of the high mountain roads have so far been positive. Benefits are first of all the reduction of damage costs to the heavy snow cutter equipment as the equipment can navigate by high accuracy and precision on the road. Damage costs are also reduced related to safety fences and other road furniture not being hit by the heavy machinery. Our mountain roads can from now on also be re-opened without extensive use of roadside installed winter poles. The quantity of snow to be removed is also considerably reduced as the snow removal equipment is working more precisely. The Norwegian Public Roads Administration has also started to use GPS equipment in the road construction sector. The use is based on experience from using the GPS in re-opening the winter roads with the same procedure of identifying the fixed points of reference. When this procedure is fulfilled, it is possible to use the GPS in various road construction processes.