US Bridges

Is 70 W over Missouri Rvr Cst Main S

Fair

St. Louis County, Missouri · S 32 T 47 N R 5 E · Structure no. 6672

Built
1958
67 years old, rebuilt 2011
Condition
Fair
inspected December 2023
Type
Truss - Thru
Steel Continuous
Length
4,083 ft
3 main spans
Daily traffic
84,031
2024 count
Owner
State
State Highway Agency

About this bridge

Is 70 W over Missouri Rvr Cst Main S is a steel continuous truss - thru carrying Is 70 W over Missouri Rvr Cst Main S in St. Louis County, Missouri. It was built in 1958 and reconstructed in 2011, so it is 67 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 84,031 vehicles a day, roughly 12% of them trucks, projected to reach 105,039 by 2044. The structure is 4,083 ft (1,244.5 m) long and 63 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesIs 70 W
CrossesMissouri Rvr Cst Main S
LocationS 32 T 47 N R 5 E
RouteInterstate 70
CountySt. Louis County
StateMissouri
Coordinates38.76486, -90.48402
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65.5 US tons
Inventory rating39.7 US tons

Structure

Structure typeTruss - Thru
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3 (+17 approach)
Design loadHS 20 + Mod
Structure length4,083 ft (1,244.5 m)
Longest span480 ft (146.3 m)
Deck width63 ft (19.1 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deck20 ft (6.1 m)

Traffic and service

Average daily traffic84,031 (2024)
Projected traffic105,039 by 2044
Trucks12%
Lanes on structure5
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and waterway
Detour if closed0.6 mi (1 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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$159.6 million (2025 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was Is 70 W over Missouri Rvr Cst Main S built?

It was built in 1958, making it 67 years old in 2025. It was reconstructed in 2011.

What condition is Is 70 W over Missouri Rvr Cst Main S 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 December 2023.

How much traffic does Is 70 W over Missouri Rvr Cst Main S carry?

About 84,031 vehicles per day (2024 count), of which roughly 12% are trucks.

How long is Is 70 W over Missouri Rvr Cst Main S?

The structure is 4,083 ft (1,244.5 m) long with a longest span of 480 ft (146.3 m) and a deck 63 ft wide.

Who owns Is 70 W over Missouri Rvr Cst Main S?

It is owned by the State Highway Agency.