US Bridges

Hillsboro RD over Terre Bleue

PoorPosted for load

St. Francois County, Missouri · S 2107 T 37 N R 5 E · Structure no. 13972

Built
1935
90 years old
Condition
Poor
inspected December 2024
Type
Arch - Deck
Masonry
Length
203 ft
9 main spans
Daily traffic
2,242
2023 count
Owner
County
County Highway Agency

About this bridge

Hillsboro RD over Terre Bleue is a masonry arch - deck carrying Hillsboro RD over Terre Bleue in St. Francois County, Missouri. It was built in 1935, so it is 90 years old, older than the Missouri average of 45.1 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.

It carries about 2,242 vehicles a day, roughly 10% of them trucks, projected to reach 3,363 by 2043. The structure is 203 ft (61.9 m) long and 22 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

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CarriesHillsboro RD
CrossesTerre Bleue
LocationS 2107 T 37 N R 5 E
RouteCounty Highway 53
CountySt. Francois County
StateMissouri
Coordinates37.92748, -90.47201
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating31.7 US tons
Inventory rating17.9 US tons

Structure

Structure typeArch - Deck
MaterialMasonry
DeckConcrete, cast-in-place
Main spans9
Design loadOther
Structure length203 ft (61.9 m)
Longest span30 ft (9.1 m)
Deck width22 ft (6.8 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,242 (2023)
Projected traffic3,363 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.3 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Hillsboro RD over Terre Bleue built?

It was built in 1935, making it 90 years old in 2025.

What condition is Hillsboro RD over Terre Bleue in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in December 2024.

How much traffic does Hillsboro RD over Terre Bleue carry?

About 2,242 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is Hillsboro RD over Terre Bleue?

The structure is 203 ft (61.9 m) long with a longest span of 30 ft (9.1 m) and a deck 22 ft wide.

Who owns Hillsboro RD over Terre Bleue?

It is owned by the County Highway Agency.