Is 57 S over Big Lk Byu
Mississippi County, Missouri · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Is 57 S over Big Lk Byu in Mississippi County, Missouri, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1974, making it 51 years old at the 2025 inventory.
- It carries about 6,589 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 62 of the 99 inventoried bridges in Mississippi County rated fair (62.6%); 10 (10.1%) 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 January 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 → (37.00802, -89.22319)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 672 ft |
| Location | S 9 T 27 N R 17 E |
| NBI structure number | 1776 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | January 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Missouri department of transportation.
Busiest bridges in Mississippi County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Is 57 S over Ash Slu Dtch | 1959 | 17,923 | Fair |
| Is 57 S over Drain Dtch | 1959 | 17,660 | Fair |
| Is 57 S over Lateral Dtch #2 | 1959 | 15,417 | Fair |
| Is 57 S over Mississippi Rvr | 1976 | 11,453 | Fair |
| Is 57 S over Lateral Dtch #2 | 1975 | 6,589 | Fair |
| Is 57 S over Lateral Dtch #23 | 1974 | 6,589 | Fair |
All bridges nearby: Mississippi County, MO bridge conditions · every bridge in Mississippi County · Missouri bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.