I've seen many times working on the same part, why?

In Yokohama City, construction (new construction, repair, etc.) in public utilities, such as water supply, sewerage, gas, etc., where roads are buried, will be coordinated with companies and multiple constructions will be carried out continuously. After the construction of one company, temporary pavement (temporary restoration) of roads will be carried out so that construction of the next company can be carried out immediately.
For this reason, construction of the same part will be performed several times in a short period of time, but prevention of excavation of roads compared to the case where each company performs construction for its own convenience without coordination between companies and We believe that it is useful for road users because we can shorten the construction period.