Irrsr Nd Hiway 31 over Cannonball River
Grant County, North Dakota · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Irrsr Nd Hiway 31 over Cannonball River in Grant County, North Dakota, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 2014, making it 11 years old at the 2025 inventory.
- It carries about 260 vehicles a day (traffic count year 2019).
- Its listed owner is the state highway agency.
- It is one of 23 of the 59 inventoried bridges in Grant County rated good (39.0%); 6 (10.2%) 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 May 2023, on a 24-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (46.1265, -101.33282)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 317 ft |
| Location | 13 North of Sd Border |
| NBI structure number | 0031012802 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | May 2023 |
| 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 North Dakota department of transportation.
Busiest bridges in Grant County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Nd Highway over Creek | 1950 | 950 | Fair |
| Nd Highway over Branch-antelope Creek | 1952 | 700 | Fair |
| Nd Highway 21 over Creek | 1994 | 590 | Fair |
| Nd Highway 49 over Antelope Creek | 1988 | 580 | Good |
| Nd Highway 31 over Dogtooth Creek | 2024 | 420 | Good |
| Nd Highway 49 over Cannonball River | 1970 | 420 | Fair |
All bridges nearby: Grant County, ND bridge conditions · every bridge in Grant County · North Dakota bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.