US Bridges

Mo 21 S over Mattese CR

Poor

St. Louis County, Missouri · S 1988 T 44 N R 6 E · Structure no. 956

Built
1967
58 years old
Condition
Poor
inspected November 2023
Type
Culvert
Concrete Continuous
Length
32 ft
3 main spans
Daily traffic
25,160
2024 count
Owner
State
State Highway Agency

About this bridge

Mo 21 S over Mattese CR is a concrete continuous culvert carrying Mo 21 S over Mattese CR in St. Louis County, Missouri. It was built in 1967, so it is 58 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 25,160 vehicles a day, roughly 5% of them trucks, projected to reach 35,224 by 2044. The structure is 32 ft (9.7 m) long. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesMo 21 S
CrossesMattese CR
LocationS 1988 T 44 N R 6 E
RouteState Highway 21
CountySt. Louis County
StateMissouri
Coordinates38.51436, -90.36969
Functional classUrban Other Principal Arterial

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating96.2 US tons
Inventory rating57.5 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans3
Design loadHS 20
Structure length32 ft (9.7 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25,160 (2024)
Projected traffic35,224 by 2044
Trucks5%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$306,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mo 21 S over Mattese CR built?

It was built in 1967, making it 58 years old in 2025.

What condition is Mo 21 S over Mattese CR in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in November 2023.

How much traffic does Mo 21 S over Mattese CR carry?

About 25,160 vehicles per day (2024 count), of which roughly 5% are trucks.

How long is Mo 21 S over Mattese CR?

The structure is 32 ft (9.7 m) long with a longest span of 10 ft (3 m).

Who owns Mo 21 S over Mattese CR?

It is owned by the State Highway Agency.