US 20 US 52 over Drainage Ditch
Dubuque County, Iowa · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 20 US 52 over Drainage Ditch in Dubuque County, Iowa, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1957 and reconstructed in 1988, making it 68 years old at the 2025 inventory.
- It carries about 18,500 vehicles a day (traffic count year 2022).
- Its listed owner is the state highway agency.
- It is one of 141 of the 346 inventoried bridges in Dubuque County rated fair (40.8%); 25 (7.2%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated March 2024, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (42.44047, -90.83474)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 23 ft |
| Location | 0.8 Mi. E of Jct. SR Y21 |
| NBI structure number | 000000000605960 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | March 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Dubuque County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 20 over N Branch Catfish Creek | 1939 | 33,600 | Fair |
| US 61 & 151 over Peosta Chl & City St | 1991 | 22,300 | Fair |
| US 61 & 151 over Mississippi River Island | 1982 | 20,400 | Fair |
| US 20 over Miss. River Hwy & RR | 1943 | 17,700 | Fair |
| EB US 20 over Mid Br Catfish Ck Cc RR | 1995 | 14,300 | Good |
| WB US 20 over Mid Br Catfish Ck Cc RR | 1961 | 14,300 | Fair |
All bridges nearby: Dubuque County, IA bridge conditions · every bridge in Dubuque County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.