US Bridges

Is 170 E over Cst Airport RD

Fair

St. Louis County, Missouri · S 2979 T 46 N R 6 E · Structure no. 2565

Built
1980
45 years old
Condition
Fair
inspected September 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
188 ft
2 main spans
Daily traffic
46,871
2024 count
Owner
State
State Highway Agency

About this bridge

Is 170 E over Cst Airport RD is a steel continuous stringer/multi-beam or girder carrying Is 170 E over Cst Airport RD in St. Louis County, Missouri. It was built in 1980, so it is 45 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 46,871 vehicles a day, roughly 12% of them trucks, projected to reach 58,589 by 2044. The structure is 188 ft (57.3 m) long and 59 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesIs 170 E
CrossesCst Airport RD
LocationS 2979 T 46 N R 6 E
RouteInterstate 170
CountySt. Louis County
StateMissouri
Coordinates38.74971, -90.33827
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
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.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.5 US tons
Inventory rating37.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length188 ft (57.3 m)
Longest span94 ft (28.7 m)
Deck width59 ft (17.9 m)
Roadway width56 ft (17.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic46,871 (2024)
Projected traffic58,589 by 2044
Trucks12%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
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$2.2 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Is 170 E over Cst Airport RD built?

It was built in 1980, making it 45 years old in 2025.

What condition is Is 170 E over Cst Airport RD 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 September 2024.

How much traffic does Is 170 E over Cst Airport RD carry?

About 46,871 vehicles per day (2024 count), of which roughly 12% are trucks.

How long is Is 170 E over Cst Airport RD?

The structure is 188 ft (57.3 m) long with a longest span of 94 ft (28.7 m) and a deck 59 ft wide.

Who owns Is 170 E over Cst Airport RD?

It is owned by the State Highway Agency.