City Bridge Maintenance Category
According to the status of a bridge in the road system in the city, the city bridge maintenance should be divided into the following five categories:
1. Conservation class city bridge - a bridge large bridges and special structures.
2. Conservation class city bridge - urban freeway bridge online.
3. Conservation class city bridge - the city on the main road bridge.
4.Conservation class city bridge - urban sub dry road bridge.
5.Conservation class city bridge - City branch and neighborhood road bridge.