US Bridges

Mo 231 S over Meramec Rvr

Fair

St. Louis County, Missouri · S 33 T 43 N R 6 E · Structure no. 4005

Built
1995
30 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
1,235 ft
3 main spans
Daily traffic
9,048
2024 count
Owner
State
State Highway Agency

About this bridge

Mo 231 S over Meramec Rvr is a steel continuous stringer/multi-beam or girder carrying Mo 231 S over Meramec Rvr in St. Louis County, Missouri. It was built in 1995, so it is 30 years old, younger 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 5 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 9,048 vehicles a day, roughly 7% of them trucks, projected to reach 12,667 by 2044. The structure is 1,235 ft (376.4 m) long and 46 ft wide. If it were closed, the detour would be 18 mi (29 km).

Location

Open in Google Maps
CarriesMo 231 S
CrossesMeramec Rvr
LocationS 33 T 43 N R 6 E
RouteState Highway 231
CountySt. Louis County
StateMissouri
Coordinates38.41957, -90.34683
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.5 US tons
Inventory rating37.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+10 approach)
Design loadHS 20 + Mod
Structure length1,235 ft (376.4 m)
Longest span170 ft (51.8 m)
Deck width46 ft (13.9 m)
Roadway width43 ft (13 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,048 (2024)
Projected traffic12,667 by 2044
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed18 mi (29 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 Mo 231 S over Meramec Rvr built?

It was built in 1995, making it 30 years old in 2025.

What condition is Mo 231 S over Meramec Rvr 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 August 2024.

How much traffic does Mo 231 S over Meramec Rvr carry?

About 9,048 vehicles per day (2024 count), of which roughly 7% are trucks.

How long is Mo 231 S over Meramec Rvr?

The structure is 1,235 ft (376.4 m) long with a longest span of 170 ft (51.8 m) and a deck 46 ft wide.

Who owns Mo 231 S over Meramec Rvr?

It is owned by the State Highway Agency.