US Bridges

Is 170 E over Rt D

Fair

St. Louis County, Missouri · S 33 T 46 N R 6 E · Structure no. 2718

Built
1980
45 years old
Condition
Fair
inspected October 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
182 ft
3 main spans
Daily traffic
95,057
2024 count
Owner
State
State Highway Agency

About this bridge

Is 170 E over Rt D is a steel continuous stringer/multi-beam or girder carrying Is 170 E over Rt D 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 95,057 vehicles a day, roughly 4% of them trucks, projected to reach 118,821 by 2044. The structure is 182 ft (55.5 m) long and 111 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesIs 170 E
CrossesRt D
LocationS 33 T 46 N R 6 E
RouteInterstate 170
CountySt. Louis County
StateMissouri
Coordinates38.68647, -90.35416
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionOctober 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 geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68.5 US tons
Inventory rating40.7 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length182 ft (55.5 m)
Longest span98 ft (29.9 m)
Deck width111 ft (33.8 m)
Roadway width108 ft (32.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic95,057 (2024)
Projected traffic118,821 by 2044
Trucks4%
Lanes on structure6
Traffic directionTwo-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 proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was Is 170 E over Rt D built?

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

What condition is Is 170 E over Rt D 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 October 2024.

How much traffic does Is 170 E over Rt D carry?

About 95,057 vehicles per day (2024 count), of which roughly 4% are trucks.

How long is Is 170 E over Rt D?

The structure is 182 ft (55.5 m) long with a longest span of 98 ft (29.9 m) and a deck 111 ft wide.

Who owns Is 170 E over Rt D?

It is owned by the State Highway Agency.