aid for solving the procurement, transformation and presenta-
tion of terrain information.
Experiences have also shown that those organizations following
a logical and simple system for the highway design have made the
best success and received the best result.
The increasing speed and flow of the traffic during the recent
decade has also increased the requirements on the technical stan-
dard of the highways or highway system. The introduction of ad-
vanced elements of road alignment and the steadily growing inte-
rest in the aesthetic environment problems require more complete
information on the terrain or landscape and this information
must be available on the right time, of the optimal quality and
be presented in a way, that can be accepted by the designer.
It could be stated that the greatest steps of the introduction
of the modern aids were taken in the first parts of the nine-
teensixties. The systems and techniques that were developed and
introduced at that time have later on been refined and improved
Step by step as the development of instruments or equipments
has continued.
It is today very interesting to study the different systems for
the application of photogrammetry to highway design that exist
in different countries. It is very easily found that the prin-
cipal differences between countries are very small if they do
exist. The differences in photogrammetric approach are mainly
based on the existance and quality of topographic maps and the
terrain topography and vegetation.
The process of highway design can generally be divided into
three different stages, namely ROute Location, Preliminary De-
sign and Final Design. This division is, from the point of view
of photogrammetry, a practical division as there is a relation
between each of the different design stages and the requirements
of the geometrical accuracy of the terrain information for that
stage. In the first two stages interest is concentrated upon
requirements on less accurate topographic information over wide
areas, while in the final stage accurate detailed information
" A ^
e 9
