Why did the truss bridge break up with the beam bridge? It needed more support.
Why did the truss bridge break up with the beam bridge? It needed more support.
Infrastructure Grade
Infrastructure Report Card
5.4% of bridges in poor condition
Total Bridges
4,646
Poor Condition
250(5.4%)
Avg Bridge Age
46 yrs
Trend
Stable
| Metric | Idaho | National Avg | Trend |
|---|---|---|---|
| % Poor Condition | 5.4% | 6.7% | Stable |
| vs. National Average | -1.3 pts | -- | -- |
| Average Bridge Age | 46 yrs | 48 yrs | -- |
| Good or Better | 2,474(53.3%) | -- | -- |
Grade Scale
Percentage of bridges in poor condition over time. The dashed line shows the national average for comparison.
Total Bridges
4,646
Poor Condition
250(5.4%)
Average Age
46 yrs
Daily Crossings
15.4M
Good or Better
2,474(53.3%)
These bridges have at least one major component rated "5" (Fair) — one step above the poor threshold. Sorted by daily traffic to highlight highest-impact structures at risk.
| Bridge | Location | Deck | Super | Sub | Daily Traffic |
|---|---|---|---|---|---|
| I 84 ;US 20-26 | Canyon County | 5 | 6 | 6 | 58,000 |
| SH 55;EAGLE ROAD | Ada County | 6 | 5 | 6 | 58,000 |
| US 20 | Bonneville County | 6 | 5 | 6 | 38,000 |
| US 20 | Ada County | 5 | 6 | 6 | 35,500 |
| US 95 | Kootenai County | 5 | 5 | 5 | 33,500 |
| STC8223;NORTHSIDE | Canyon County | 6 | 5 | 6 | 29,000 |
| US 20 EB-WB | Jefferson County | 7 | 5 | 6 | 28,500 |
| SMA 7406;PANCHERI | Bonneville County | 5 | 5 | 6 | 26,000 |
| SMA 7563;OVERLAND | Ada County | 5 | 5 | 7 | 26,000 |
| SMA9463;FIVE MILE | Ada County | 7 | 5 | 6 | 24,000 |
| STP8393;FRANKLIN B | Canyon County | 5 | 6 | 6 | 22,000 |
| US 12 | Nez Perce County | 6 | 5 | 6 | 21,000 |
| I 15B ;BROADWAY ST | Bonneville County | 6 | 5 | 6 | 20,500 |
| US 26 EBL & WBL | Bingham County | 6 | 6 | 5 | 18,000 |
| I 15B ;BROADWAY ST | Bonneville County | 6 | 6 | 5 | 18,000 |
The 10 bridges in poorest condition, ranked by lowest sufficiency rating.
over CDA RIVER;SPRINGSTON BR
over REYNOLDS CREEK
over BEAR RIVER;E.WESTON BR.
over S.FK.COEUR DALENE RIVER
over N.FK.EAST RIVER
over CO.RD.;STODDARD CREEK IC
over CLOVER CREEK
over THIRD FK.CHIEF EAGLE EYE
over M.F.CLWATER R.;E.KOOSKIA
over WEISER RIVER
States with similar infrastructure profiles, ranked by percentage of bridges in poor condition.
Grading: Grades are based on the percentage of bridges classified as "poor condition." A bridge is in poor condition when at least one major component (deck, superstructure, or substructure) is rated 4 or below on the NBI 0-9 scale.
Data Source: Federal Highway Administration (FHWA) National Bridge Inventory (NBI). Data is updated annually. BridgeStats is not affiliated with or endorsed by the FHWA.
Watchlist Criteria: Bridges with any component rated "5" (Fair) are one step from the poor threshold of 4 and are flagged for monitoring. These bridges are not yet in poor condition but may deteriorate without maintenance.