Laser Lane Marking

In the E18 Bjørvika, 4,500m long highway tunnel in the Norwegian capital Oslo, special re_ectors were designed and manufactured in four di_erent materials for durability testing of light sources to improve the visual aid of diverting tra_c into bi-directional tra_c in one tube. A controlled beam of yellow light to hit the road surface and make a bright spot was decided. An optical _bre carries the light from the lasers out into the tunnel. Lens assemblies in the roof of the tunnel generate the correct laser beam shapes on the re_ectors in the ground. The result is a very visible line of points on the road. The trial is carried out on behalf of NPRA, the Norwegian Public Roads Administration.