Rt Z S over Dardenne CR
St. Charles County, Missouri · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Rt Z S over Dardenne CR in St. Charles County, Missouri, 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 2004, making it 21 years old at the 2025 inventory.
- It carries about 8,589 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 138 of the 419 inventoried bridges in St. Charles County rated good (32.9%); 12 (2.9%) 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 September 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 → (38.73461, -90.87934)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 8 | 8 | Very good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous prestressed concrete stringer or multi-beam girder |
| Length | about 220 ft |
| Location | S 738 T 46 N R 1 E |
| NBI structure number | 29781 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 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 Missouri department of transportation.
Busiest bridges in St. Charles County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Is 70 E over Sandford CR | 1953 | 122,262 | Fair |
| Is 70 E over Cole CR | 1953 | 109,398 | Fair |
| Is 70 E over Belleau CR | 1955 | 108,528 | Fair |
| Is 70 E over Rt K Co OR70W to OR70E | 1955 | 107,979 | Fair |
| Is 70 E over Gilmore Br | 1950 | 87,827 | Fair |
| Is 70 W over Cst S 5TH St | 1977 | 84,031 | Fair |
All bridges nearby: St. Charles County, MO bridge conditions · every bridge in St. Charles County · Missouri bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.