field in the instrument to the reading of results on scales. For this 
reason all recording of data from the measurements in the stereoauto- 
graph A 8 will be made automatically with the help of a coordinate 
recorder and printer Ek3 provided with Facit punch equipment. The 
data-machine program has been worked out for Facit EDP. 
For the design-work the program has been divided up as follows. 
1. Transformation of model coordinates to ground coordinates. The 
program has been drawn up by Tekn. lic. A. Häkansson. 
2. Translation of the transformed coordinates to cross-section data, 
distance from center-line and height, distance between cross-sections. 
Possibilities of interpolation between points not lying on the normal 
line of the cross-section are afforded. The program is being worked out 
by Nordisk ADB, Stockholm. 
3. After the balancing of the road-line and examination of the ground 
the mass calculation is carried out with the data machine. 
4. To the extent required the cross-sections, with the type-section of 
the road can be drawn with the help of a line-plotter. 
The technique of electronic calculation plays an important róle also 
at the stage of preliminary planning. In connection with or after the 
drawing of the planning map with altitude curves in the stereoauto- 
graph A 8 one can with the A 8, the coordinate recorder and the data 
machine automatically record longitudinal profile and parallel profiles 
or cross-sections for the road-line or for its possible alternatives, which 
is of value for the fitting in in detail in the terrain. 
Such a large number of assessments of, inter alia, aesthetic view- 
points are required for the choice of road-line and for the fitting in of 
the same in the terrain that, at least for present conditions in Sweden, 
it does not seem possible to leave the choice of road entirely to the data 
machine. It seems more rational to plan the road-line in principle 
according to the scheme outlined above and in connection herewith to 
let the data machine perform the calculations required to assess the 
result of the alternative choices of road. 
[t must be borne in mind that "cut and fill" is only an important 
fraction in road planning and building. 
Summary 
The past three years’ experience of the photogrammetric work of the 
National Road Board has clearly demonstrated that if rationally ex- 
ploited photogrammetry is a splendid aid in the different stages of road- 
planning. The working methods described have been so designed as to 
combine the demands for a good survey over large areas in the stages 
of localization and preliminary planning with the demand for detail 
information and a high degree of accuracy in numerical data in the 
stage of design. The demand for accuracy is successively met as it be- 
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