Given the significant level of resources that has been spent on the transportation system, preserving this asset base is an important policy goal.
In the United States, the HPMS database and data from the National Bridge Inventory are used to mo or the condition of the infrastructure.
For example, in 1997.67 percent of the bridges in urban areas were considered to be in good condition 21 percent were functionally obsolete, and 12 percent were structurally deficient.
Similarly, 76 percent of the pavement on urban roads was considered to be fair, good, or very good condition: 24 percent was poor or mediocre [BTS, 1999]