The problem of referring photogrammetric datas to the terrain is 
overcome by marking the horizontal control before the photography. 
Therefor the discussion of extending the photogrammetric control by 
photogrammetric methods, aerial triangulation etc. is not only a question 
of accuracy but also a practical problem. Premarked control-points for 
the detail-photography are also used as references or supports for the 
staking of the centerline. As an example may be mentioned the French 
system (I:2) and the Swedish one (14) and (15). 
Experience has shown that if the direct reference between photogram- 
metric data and terrain data is not in order, trouble will arise at the 
construction of the road by staking out the roadbody and the constructor 
will not accept the photogrammetric datas. 
Another problem is the connection of borings to the photogrammetri- 
cally measured cross-sections in areas, where it is necessary from con- 
struction point of view to separate between rock and soil. Different 
normal road-sections are very common for rock- and soilcut. The compu- 
tor programs for the mass-computation must be so designed that the inter- 
polation at the connection between the borings and the terrainsurface is 
facilitated. 
In report (14) to the Lisbon Congress 1964 the different flying heights, 
cameras and evaluating equipments for the different phases of highway 
design was discussed for the period 1960—64. These figures are still 
valid as the development of photogrammetry has not contributed to any 
change. This fact may further underline the need of research work for 
increasing the photogrammetric quality. 
The development of the highway designing procedure has resulted into 
methods that in a good way combines photogrammetry, geodesy, data 
processing and automatic plotting. As an example may be mentioned the 
system developed and utilized in France and presented in (I: 2) which 
gives an excellent possibility of transforming the terrain data into a 
form that is acceptable from highway engineering point of view. By 
using this system the engineer gets necessary information for judging 
the result of his alternative solutions. As another example may be 
mentioned the Swedish system (14) which has been developed mostly 
along equal principles. This system allows e. g. computation of mass- 
disposition plan for the construction or drawn perspectives based upon 
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