1. INTRODUCTION 
The contribution of photogrammetric methodology to all the 
stages of a road study is recognised. 
The methodology is also offered to attend roads from all 
points of view. 
This case is more interesting for the problematic parts of 
roads, especially when we refer to roads of basic importance as 
with national roads. 
This paper is referred to such a case. 
It especially concerns a part of the national road  Athens- 
Thessaloniki at the area of Tempi (Thessalia). The national road 
and the railway lines proceed on both sides of the bed of Pinios 
River, in this area. 
The whole geomorphology and geology, especially the steep in- 
  
clinations on either side cause important problems mainly from the 
point of slopes’ stability (2). 
The combination of photo-interpretation and photogrammetric 
methods based on airphotos and terrestrial takings is studied. 
2. METHODOLOGY 
The successive steps that were followed, from the general to 
the more detailed are the following : 
2.1. General photointerpretation of the wide area from airphotos 
in scale 1:40000 (Fig.1,2). 
2.2. Photointerpretational and photogrammetric study of airphotos, 
in scale 1:20000,(mountaineous model). Especially the following 
took place .: 
2.2.1. Plotting of basic alignement and altimetric information 
(currents, contour lines) in scale 1:4000 with analogic instrument 
(Autograph Wild A7). (Fig.3). 
2.2.2. Cross sections at various characteristic positions of Pi- 
nios river and of the area on either side. (Fig.3,4). 
2.2.3. Indicative sections at longitude of torrents’ axis that 
terminate in the river.(Fig.3,5). 
2.2.4. More detailed study of areas of special interest. (Fig.3 8,6) 
990