US Bridges

Is 55 N over UP RR

Fair

Jefferson County, Missouri · S 420 T 41 N R 6 E · Structure no. 706

Built
1965
60 years old
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
156 ft
3 main spans
Daily traffic
40,739
2024 count
Owner
State
State Highway Agency

About this bridge

Is 55 N over UP RR is a steel continuous stringer/multi-beam or girder carrying Is 55 N over UP RR in Jefferson County, Missouri. It was built in 1965, so it is 60 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 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 40,739 vehicles a day, roughly 17% of them trucks, projected to reach 75,367 by 2044. The structure is 156 ft (47.5 m) long and 44 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesIs 55 N
CrossesUP RR
LocationS 420 T 41 N R 6 E
RouteInterstate 55
CountyJefferson County
StateMissouri
Coordinates38.28347, -90.40319
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating76.4 US tons
Inventory rating45.6 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length156 ft (47.5 m)
Longest span58 ft (17.7 m)
Deck width44 ft (13.3 m)
Roadway width41 ft (12.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic40,739 (2024)
Projected traffic75,367 by 2044
Trucks17%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
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$1.5 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Is 55 N over UP RR built?

It was built in 1965, making it 60 years old in 2025.

What condition is Is 55 N over UP RR 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 November 2024.

How much traffic does Is 55 N over UP RR carry?

About 40,739 vehicles per day (2024 count), of which roughly 17% are trucks.

How long is Is 55 N over UP RR?

The structure is 156 ft (47.5 m) long with a longest span of 58 ft (17.7 m) and a deck 44 ft wide.

Who owns Is 55 N over UP RR?

It is owned by the State Highway Agency.