Page 52 - Microsoft Word - 20120528 Unesco study

4.2.2 Reconstruction of the road network
In this paragraph estimation is made for the time required for the reconstruction works of the
damaged roads. The lengths of these damaged roads are normative. On the basis of expert
judgment for the traditional reconstruction time is estimated due to the length of the
damaged road. The estimations are given in table 4.5.

Length of the Expected
damaged road reconstruction time
1-2 km 4 weeks
2-5 km 6 weeks
5-10 km 8 weeks
10-20 km 10 weeks
15-20 km 20 weeks
20-30 km 25 weeks
Table 4.5: Expected reconstruction time

On the basis of the information in table 4.5, an estimation is made for the reconstruction
periods of the flooded road. Figure 4.6 gives an overview of the expected reconstruction time
of the flooded roads in the state of Tabasco. Using this map an accurate estimation can be
made for the indirect costs in specific regions.
Despite this map not giving hard facts regarding the indirect costs, it gives an impression of the
nuisance for the population. This is especially so in areas with a less dense road network where
a lengthy blocking of a road will probably give much nuisance to the environment.

The calculation of the reconstruction periods for flooded road segments is not trivial. While
assigning single reconstruction periods to inundated road segments is straightforward, the
actual interrupted road segments need to be grouped together to reflect the actual
progression of repair works; e.g. when 10 small segments within a single road are washed
away because of flooding, the repairs will most probably not take place in parallel but rather
sequentially. Therefore the reconstruction period of road segments might take longer than the
individual flooded portions may require. To overcome this problem, a clustering algorithm is
applied that groups road segments within a predefined radius (5km). The assigned
reconstruction period is based on the total length of the clustered segments. Note, that within
urban centers, road repair works will probably take place in parallel.

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