US Bridges

Mcknight RD over Black CR

Good

St. Louis County, Missouri · S 16 T 45 N R 6 E · Structure no. 34706

Built
2014
11 years old
Condition
Good
inspected January 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
31 ft
1 main span
Daily traffic
13,988
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

Mcknight RD over Black CR is a prestressed concrete stringer/multi-beam or girder carrying Mcknight RD over Black CR in St. Louis County, Missouri. It was built in 2014, so it is 11 years old, younger than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 13,988 vehicles a day, roughly 1% of them trucks, projected to reach 18,884 by 2043. The structure is 31 ft (9.4 m) long and 41 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesMcknight RD
CrossesBlack CR
LocationS 16 T 45 N R 6 E
RouteCity Street 0
CountySt. Louis County
StateMissouri
Coordinates38.65019, -90.35869
Functional classUrban Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure8 Very GoodNo problems noted.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJanuary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating88.3 US tons
Inventory rating68.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length31 ft (9.4 m)
Longest span29 ft (8.8 m)
Deck width41 ft (12.4 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,988 (2023)
Projected traffic18,884 by 2043
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Mcknight RD over Black CR built?

It was built in 2014, making it 11 years old in 2025.

What condition is Mcknight RD over Black CR in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2024.

How much traffic does Mcknight RD over Black CR carry?

About 13,988 vehicles per day (2023 count), of which roughly 1% are trucks.

How long is Mcknight RD over Black CR?

The structure is 31 ft (9.4 m) long with a longest span of 29 ft (8.8 m) and a deck 41 ft wide.

Who owns Mcknight RD over Black CR?

It is owned by the City or Municipal Highway Agency.