US Bridges

Main ST over Dardenne CR

Fair

St. Charles County, Missouri · S 462 T 47 N R 3 E · Structure no. 35573

Built
1974
51 years old
Condition
Fair
inspected January 2024
Type
Slab
Concrete Continuous
Length
209 ft
4 main spans
Daily traffic
10,518
2024 count
Owner
City
City or Municipal Highway Agency

About this bridge

Main ST over Dardenne CR is a concrete continuous slab carrying Main ST over Dardenne CR in St. Charles County, Missouri. It was built in 1974, so it is 51 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 10,518 vehicles a day, roughly 5% of them trucks, projected to reach 16,303 by 2044. The structure is 209 ft (63.6 m) long and 43 ft wide. If it were closed, the detour would be 16.8 mi (27 km).

Location

Open in Google Maps
CarriesMain ST
CrossesDardenne CR
LocationS 462 T 47 N R 3 E
RouteCity Street 0
CountySt. Charles County
StateMissouri
Coordinates38.80311, -90.62884
Functional classUrban Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure8 Very GoodNo problems noted.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating55.6 US tons
Inventory rating32.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length209 ft (63.6 m)
Longest span68 ft (20.7 m)
Deck width43 ft (13 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,518 (2024)
Projected traffic16,303 by 2044
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed16.8 mi (27 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Main ST over Dardenne CR built?

It was built in 1974, making it 51 years old in 2025.

What condition is Main ST over Dardenne CR 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 January 2024.

How much traffic does Main ST over Dardenne CR carry?

About 10,518 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Main ST over Dardenne CR?

The structure is 209 ft (63.6 m) long with a longest span of 68 ft (20.7 m) and a deck 43 ft wide.

Who owns Main ST over Dardenne CR?

It is owned by the City or Municipal Highway Agency.