Flow diagram 2 
A 
  
    
Q 
Existing 
topographic 
maps 
  
  
Interpretation of 
small scale aerial 
photography 
  
  
i 
  
Construction of 
medium scale 
orthophotomap 
with contours 
or a photo- 
mosaic 
  
  
  
Photo delineation 
and plotting 
  
  
  
    
Planning the best route 
  
1. 
2. 
5. 
. 
3. 
2. 
5. 
l. 
Ze 
  
  
  
  
  
  
  
  
  
  
  
  
Delineation of l. 
potential areas e. 
for road passage, 5. 
comparison of all Le 
possible routes, 5. 
selection of the 6. 
best traverse 7. 
i 
Acquisition of l. 
large scale aerial 
photography cover- 24 
ing the area of the 
proposed route 5. 
4, 
Protting of the route/ 1. 
to the orthophotomap | 2. 
Intensive field- l. 
check and office 2. 
work % 
5. 
4, 
Delineate the region to be opened up 
Mark the cardinal points on the map 
Study the landforms 
Design a plan for small scale aerial 
photography 
landforms, drainage system, 
ruggedness of the terrain 
Topography - 
Soils - physiography, soil type and 
bearing capacity, deposits 
of gravel, sand, etc. 
Land cover - land use, property boundaries 
Forests - area under forest cover, 
tree species composition, 
stand age and stocking 
Cardinal passages: start and terminal, 
bridges, mountain passes, cutting sites, 
loading sites, sawmill, fire lookout, 
camp site, scenic areas. 
Areas with restricted passage: 
swamps and areas subject to flooding, 
unstable soil and landslides, 
protected areas (nature reserves etc.) 
obstacles (powerlines, rockoutcrops, 
houses, etc.) 
Plotting of the routes on the contourmap 
Construction of the approxümate profiles 
Discussion on critical passages 
Estimation of construction costs 
Discussion on economical aspects 
Selection of the best route 
Field reconnaissance of selected route 
Delineation of the cardinal points and 
the restricted areas. 
Photo interpretation on the topography, 
measurements of the slopes. 
Rough location of the traverse 
Road layout on the photographs 
Construction of the road profile 
Study of the cross sections along the 
traverse, 
Location of the traverse in the terrain 
Check on gradient and cross sections, 
bridge locations, obstacles, etc. 
Tests on soil bearing capacity (field and lab.) 
Determination of cuts and fills