Is 55 N over Rt Z
FairJefferson County, Missouri · S 420 T 41 N R 6 E · Structure no. 804
- Built
- 1965
- 60 years old
- Condition
- Fair
- inspected November 2024
- Type
- Slab
- Concrete Continuous
- Length
- 149 ft
- 3 main spans
- Daily traffic
- 40,739
- 2024 count
- Owner
- State
- State Highway Agency
About this bridge
Is 55 N over Rt Z is a concrete continuous slab carrying Is 55 N over Rt Z in Jefferson County, Missouri. It was built in 1965, so it is 60 years old, older than the Missouri average of 45.1 years.
The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 40,739 vehicles a day, roughly 17% of them trucks, projected to reach 75,367 by 2044. The structure is 149 ft (45.4 m) long and 40 ft wide. If it were closed, the detour would be 0.6 mi (1 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Is 55 N over Rt Z built?
It was built in 1965, making it 60 years old in 2025.
What condition is Is 55 N over Rt Z in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in November 2024.
How much traffic does Is 55 N over Rt Z carry?
About 40,739 vehicles per day (2024 count), of which roughly 17% are trucks.
How long is Is 55 N over Rt Z?
The structure is 149 ft (45.4 m) long with a longest span of 56 ft (17.1 m) and a deck 40 ft wide.
Who owns Is 55 N over Rt Z?
It is owned by the State Highway Agency.