Federal law mandates the uniform inspection of all bridges for structural adequacy at least every two years; bridges rated “deficient” are eligible for federal repair dollars. The National Bridge Inventory (NBI) is the source of the bridge data in the table and figure following, which is provided in summary form in Better Roads (see Appendix). Since the NBI contains some recent inspections and some as old as two years, the age of the “average” inspection is about one year old. So, a “December 2020” summary from the NBI would represent, on average, bridge condition as of 2019.
The condition of the nation’s highway bridges in 2020 improved slightly from 2019, the last time this assessment was completed. Of the 614,490 highway bridges reported, 45,861 (7.46%) were rated deficient for 2020 (Table 16, Percent Structurally Deficient Bridges, 2020, Figure 11). This represents a 0.16% improvement over 2019 when 46,771 of 613,517 (7.62%) were rated as deficient.
Nevada, Texas, and Arizona reported less than 2% of their bridges to be structurally deficient (at 1.28%, 1.33%, and 1.65% respectively). Rhode Island and West Virginia reported more than 20% of their bridges as structurally deficient (at 22.34% and 21.00% respectively). The majority of states (35) reported at least some improvement in the percentage of structurally deficient bridges between 2019 and 2020, with Wyoming and Pennsylvania seeing the most improvement (1.31 and 1.30 percentage points, respectively). Of the five states that reported a higher percentage of deficient bridges, only one, Hawaii, saw an increase of more than one percentage point (1.12%).
Structurally Deficient Bridges — Percent Deficient
|2020 Rank||State||Percent Structurally Deficient Bridges|