14,
The improvements have mainly concerned the terrestrial surveying
technique for measuring the required photogrammetric control.
The instruments for a combined measurement of angles and dis-
tances have meant a revolution in facilitating the photogramme-
tric technique. The instruments contain, however, a great deal
of electronic parts and the maintenance service of the instru-
ment is therefore rather complex and this fact might cause prob-
lems at least for the developina countries.
The combination of photogrammetry, surveying technique, electro-
nic computation and automatic plotting into a complete system
for the Highway Design requires access to an imposing set of
different machines, most of them requiring an acceptable level
of service. This fact has meant that there have been complica-
tions of introducing the system in developing countries without
access to the machinery or to the required service. For the success
of the application in those countries it is even more important
than elsewhere, that the principles are clear and logical and that
the system is so built up that the designer can use as simple in-
struments as possible. The development of smaller computors in
the form of deskcalculators is thus very interesting for the in-
troduction of improvement in the Highway Design. As an example
Of such a computer the Hewlett Packard, see fig 7, and the Wang
700, may be mentioned. This type of computers have a great capa-
city in relation to their size and the programming is generally
simple. The photogrammetric as well as the geodetic calculations
can be carried out with a good capacity using these small compu-
ters. One of the advantages of introducing the deskcalculators
is a psychological one, namely the fact that the designer him-
self can use the computer on his officetable without relying on
any experts in data processing. The psychological distance be-
tween the engineer and the computer will thus be minimized.
The development within the field of Data Transmission is also
Of a great interest in this connection, particularly in countries
where the access to big computers is good. Minicomputers that can
be used either as independent computers for calculations of a li-
mited size or as terminals for the transmission to a big computer
for complex calculations will also push the development of the
Highway Design technique forward.
€ 9
(o 9
