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tendency strongly. 
(2Comparison with the situation before the 
earthquake disaster: An analysis results in each area 
are shown in the Figure 8-3. and the Figure 9-3, 
respectively. In the Rokkoumichi area, the style that the 
traffic concentrates on the street which was left after 
suffered comes out clear. When the street with large width 
is blocked, the adjacent small streets are chosen at high 
frequency while other streets with large width are not 
chosen. We think that one pattern of the traffic congestion 
at the earthquake disaster occurred probably under such a 
situation. On the other hand, in Kasuganomichi area, 
because comparatively a lot of streets are left, pathfinding 
concentration is few. However, there is a street where the 
detour is chosen in large width street which has been 
blockaded and it is expected that the traffic concentration 
takes place there. The width of these streets is narrow for 
the most part. As for the possibility to become the 
situation which is the same in Rokkoumichi, the degree of 
the damage is different only and is this area. 
4. Discussion 
In this study, we processed from the acquisition of 
network data and integration of the data base to the 
analysis and the output using GIS. Now, we considers the 
advantage and the problem of GIS for the grasping of a 
street function. 
4. 1. Role of GIS for the street function grasping 
The role of GIS in this study is as follows. Street function 
grasping was effectively carried forward by these roles. 
(1) Integration of the data base: In this study, the 
authors gave ID number to the link before acquiring data 
in an aim for the common use of data. As a result, the 
data were smoothly integrated. Also, the merit of the GIS 
utilization when examining dysfunction of the street is to 
grasp visually "to what degree and where has the fault 
took place”, in addition grasping the degree of the fault 
quantitatively. 
(2) Execution of the analysis by the topological data: 
Link data was structured, provided with a topology and 
was processed in the form with which it is possible to 
analyze a network. As a result, the simulation to 
reproduce a traffic situation in the earthquake disaster has 
become possible by using the technique of the pathfinding. 
The technique of the network analysis has the room for 
further improvement in the network analysis. However, the 
frame of the basic processing has been completed. It 
opens the way for the establishment of the analysis 
technique and the possibility of the practical use, too, in 
the future. 
4. 2. Problem of GIS use 
(1) Establishment of the analysis technique: In the 
pathfinding, we guessed passage time only from the width 
and the length of the link. Idealistically, we should have 
383 
introduced a formula of the relation between the width and 
the speed based on the traffic engineering. Also, the 
analyzed result has not been verified by the spot 
investigation etc. The verification of the analysis result 
which was based on the hearing investigation is hoped for. 
Also, the more realistic analysis becomes possible by 
adding the data of the traffic regulation and obstacles in 
normal time. 
(2) Speeding up of data base construction: About three 
day is necessary for one area to construct a data base. 
This is no problem, if the study and the plan etc. are its 
purpose. However, GIS will show real value only if it is 
used to support some kinds of decision making. The data 
of the network and the street structure can be prepared in 
normal time. Therefore, the key is how to take in the data 
of the blockade such as the pole falling and debris 
efficiently. By this study, we could establish this system. 
But we cannot deny that we had not a small confusion as 
to the difference in the recognition of data measurement 
and the definition of common use of data. Therefore, it is 
hoped to establish and speed up the system from data 
acquisition and analysis to the output. 
5. Epilogue 
By this study, the authors made GIS the saucer of the 
information and tried the integration and the analysis of 
the information on the dysfunction at the street. Generally, 
it is said that "the success or failure of the GIS project 
depends on how to build a data base smoothly first". The 
efficient data base building became possible by investing 
a analytical plotter into the flow of the data acquisition. 
The air-photograph can record the information in concert 
with the change ofthe time when the phenomenon in the 
ground changes every moment like the time of the 
earthquake disaster. Also, the air-photograph will be 
valuable sources for analyzing because the condition in 
the past can be reproduced afterwards. It is possible to 
realize efficient processing process by adding GIS 
processing thereto, and it will be possible to handle the 
air-photograph information more effectively. 
Finally, we point out the problem in grasping a function of 
street using GIS in the following. 
- Integration and speeding up of the system from the 
data acquisition to the output. 
: Establishment of processing process for the smooth 
data exchange. 
: Realization of simple system which is available for 
an inexperienced person of GIS. 
- Establishment of technique about street blockade and 
traffic route evaluation. 
Reference: 
leda H. Kaminishi S. Inomata T. Suzuki T., 1995. A Street 
Blockade by Debris of Hanshin Quake. PROCEEDINGS 
OF INFRASTRUCTURE PLANNING, 18(2), pp847-850. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996