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of the terrain. The efficiency of the photogrammetric technique 
is correlated with the roughness of the terrain and the size of 
the project. The vegetation limits the efficiency. 
If the photogrammetric technique is used for the terrain infor- 
mation the following system or method can be used: 
A traverse with a side-length of approx. 200 m is reconnoitered, 
marked and signalized along the centerline before the photo- 
graphy in order to serve as planimetric control for the photo- 
grammetric evaluation. The traverse points are located in such 
a way that they can also be used as control points for the 
Setting out of the centerline. Terrain details, identified in 
the photographs after the photography, are mainly used for the 
vertical control. 
The aerial photographs are taken from a flying height of 600 - 
1000 m. 
The evaluation of the photographs consists of measurements of 
longitudinal and transverse profiles and of preparing detail 
maps at the scale of 1:500 - 1:1000 with contours at an inter- 
val of 0.5 - 1 m. The maps are used for the final design of 
interchanges, bridges etc. 
The photogrammetric measurements of longitudinal and trans- 
verse profiles, the model coordinates, are automatically re- 
gistered on paper tape or punch cards by a registering device, 
connected to the evaluation equipment. The model coordinates 
are first transformed into the ground system of coordinates 
and then into the system of the centerline before they are 
shown in the form of longitudinal and transverse profiles. 
The computer programs generally allow the insertion of terres- 
trial measurement in cases, where gaps occur due to vegetation 
etc. 
Ordinarily the topographic data must also be complemented by 
geological-geotechnical data from borings etc, as the design 
of the roadbody also depends on soil conditions.