25th Annual Highway Report: Structurally Deficient Bridges

Federal law mandates the uniform inspection of all bridges for structural and functional 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 below, although we use summaries provided 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 2019” summary from the NBI would represent, on average, bridge condition as of 2018.

The condition of the nation’s highway bridges in 2019 improved slightly from 2018, the last time this assessment was completed. Of the 613,517 highway bridges reported, 46,771 (7.62%) were rated deficient for 2019 (Table 15, Percent of Structurally Deficient Bridges, 2019, Figure 11). This represents a 1.24%  improvement over 2018 when 54,254 of 612,408  (8.86%) were rated as deficient.

Three states reported less than 2% of their bridges to be structurally deficient: Texas, Nevada, and Arizona at 1.28%, 1.36%, and 1.81%, respectively.

One state reported more than 20% of its bridges as structurally deficient: Rhode Island at 23.08%. The majority of states (45) reported at least some improvement in the percentage of structurally deficient bridges between 2017 and 2019, with  Nebraska, Missouri, and Kansas seeing the most improvement (5.9, 4.0, and 3.3 percentage points, respectively).

Of the five states that reported a higher percentage of deficient bridges, only one saw increases of more than one percentage point: Hawaii at 1.05% (from 5.81% to 6.86%).

Structurally Deficient Bridges — Percent Deficient (2019)