Photogrammetry and Electroning Computation 
in Highway Planning 
By C.-O. Ternryd, Stockholm 
Survey of the work carried on at the Photogrammetric Section of 
the Swedish National Road Board. 
The intensive development in the field of traffic and higway tech- 
niques in recent years has made heavy demands on the apparatus whose 
function it is to plan the highway system that is to serve the constantly 
growing traffic. The large sums that are spent annually for transporta- 
tion costs in the form of traffic costs and pure highway costs demand 
increasingly that road-planning be carried out in such a way that the 
results of the total expenditure are as nearly optimal as possible. The 
present extent of road-planning and the extent that it will come to have 
in Sweden in the future have motivated the intensive utilization of all 
the modern aids offered by modern techniques. 
In this connection the air-photograph has proved to be an aid which 
affords good possibilities of improving the quality of planning and of 
considerably increasing the capacity of planning work by eliminating 
much of the routinework involved. 
For these reasons a photogrammetric section was established at the 
National Road Board in the year 1957. The main tasks of this depart- 
ment are to investigate and further to develop the rôle of photogram- 
metry, and to introduce the results arrived at in Swedish road-planning. 
In order to utilize photogrammetry rationally in road-planning it 1s 
necessary to divide it into three main stages, viz., localization, prelimi- 
nary planning and design. The first stage, localization, refers to plann- 
ing carried to the point at which one has one or more strips of terrain 
of about one or two km in breadth within which the road-project should 
be located. This is followed by the preliminary planning work to the 
point at which a line of road is obtained that is ready to be staked out 
in the terrain. The design implies the detailed shaping of the road-body 
and results in plans and specifications for the contractor. 
It is only to be expected that the different stages of the work should 
make different demands upon photogrammetry from the viewpoints of 
treatment and accuracy. 
What is essential for the first two stages is a good survey over a 
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