Road Tunnels Manual
Due to the amount of technical equipment in an urban road tunnel it is of utmost importance to keep all documentation about the equipment up to date, not only after major refurbishments, but whenever a change is made.
A refurbishment usually requires updating documentation of:
When planning a major refurbishment it is recommended to use the same approach as for a new design.
General recommendations on refurbishment can be found in the PIARC Report 2008R15EN "Urban road tunnels : recommendations to managers and operating bodies for design, management,operation and maintenance".