REPORT OF COMMISSION VII 
GVII-51 
parable scale of 1:500 of which considerable numbers have been produced. 
The 1:480 railway surveys are used extensively for the purpose of scheming 
reconstruction work of station, goods and marshalling yard layouts and also 
permanent way layouts and the amount of detail required for this purpose is 
considerable. It requires, for example, the plotting of such details as the tips 
of switches and noses of crossings, manhole and inspection covers, mile posts 
and gradient posts. It has been found necessary in some cases to ease the prob 
lem of interpreting and locating some of these objects, especially on the perma 
nent way, by pre-marking them on the ground with white paint, but on the 
other hand some surveys of this type have been carried out successfully entirely 
without pre-marking. 
Urban Planning 
Urban planning has been informally defined (Witenstein 1955) as an orderly 
process of organizing or altering the physical plant of a city to meet changing 
economic and social needs of the community, and guiding its future growth 
and development. The practicability of aerial survey to provide the large-scale 
maps necessary to such planning has long been recognized. Also, the prepara 
tion of such maps in itself requires a certain amount of photographic interpreta 
tion in the correct identification and symbolization of objects observed on the 
photography. 
However, the application of photographic interpretation to the problem of 
analyzing the urban area for purposes of urban planning, has lagged. One of 
the reasons is that adequate photographic interpretation techniques for this type 
of work have been slow in development. However, experimental work is going 
forward in this field in Holland, the United States, and other countries. A few 
examples of these applications follow: 
In the United States, the City of Rockville, a suburban town in the metro 
politan area of Washington, D. C., has been for the past four years, serving as 
a test area for various applications of aerial survey to urban planning and ad 
ministration problems (Witenstein 1954 & 1955). Here photography has been 
used in a study of the five main aspects of urban living: 
Land-use 
Movement of people and goods 
Utilities, community services, and public facilities 
Industry and commerce 
Recreation. 
The results of these studies have been assembled on overlays keyed to 
photographic mosaics of the area. These overlays can be used singly or in com 
bination as an aid to urban planning, in predicting the effect of any of the 
factors portrayed on present or proposed urban development. 
At Oak Ridge, Tennessee, U.S.A., photography has been used to readjust 
property lines on a community of more than 6,000 dwellings (Warnick 1954). 
Since property boundaries had not been established in the original settlement, 
it was necessary to study each residence on aerial photography enlarged to 
1/600, in conjunction with street survey drawings. The landscaping and other 
improvements accomplished around the houses, as determined from the photog 
raphy, were used as an aid in establishing the most acceptable property divi 
sions. This project, which might have taken several years by ground survey, 
was accomplished in a relatively short time and with a minimum of cost. 
In other U. S. cities, photographic interpretation has been used in estimating