Vision length (data type 113 in the road register)

The data cover the road network maintained by the Finnish Transport Agency. Vision length is the distance at which the driver of a passenger car can unobstructedly see a point on the road at a height of 110 cm. The vision length is measured at the extreme values of vision and assumes that the vision length changes linearly between them. Separate measurement instructions have been given for applying for long and short vision. Measurements and pre-processing of results for the road register are handled centrally. Sights are only recorded in the inventory direction. Seeing the opposite direction is possible to obtain an estimate using mathematical methods or to order a separate measurement.