US Bridges

Service Road over Alley Spring Branch

FairPosted for load

Shannon County, Missouri · Adjacent to Alley Spring · Structure no. 6640005P0000000

Built
1975
50 years old, rebuilt 1983
Condition
Fair
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
91 ft
2 main spans
Daily traffic
10
2019 count
Owner
Federal
National Park Service

About this bridge

Service Road over Alley Spring Branch is a steel stringer/multi-beam or girder carrying Service Road over Alley Spring Branch in Shannon County, Missouri. It was built in 1975 and reconstructed in 1983, so it is 50 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. Its operating status is: posted for load restriction.

It carries about 10 vehicles a day, projected to reach 12 by 2039. The structure is 91 ft (27.7 m) long and 15 ft wide.

Location

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CarriesService Road
CrossesAlley Spring Branch
LocationAdjacent to Alley Spring
RouteFederal Lands Road 161
CountyShannon County
StateMissouri
Coordinates37.15072, -91.44131
Functional classRural Minor Collector

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating17 US tons
Inventory rating10 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans2
Design loadUnknown
Structure length91 ft (27.7 m)
Longest span50 ft (15.2 m)
Deck width15 ft (4.7 m)
Roadway width11 ft (3.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10 (2019)
Projected traffic12 by 2039
Trucks0%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed—
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerNational Park Service
Maintained byNational Park Service
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$114,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Service Road over Alley Spring Branch built?

It was built in 1975, making it 50 years old in 2025. It was reconstructed in 1983.

What condition is Service Road over Alley Spring Branch 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 April 2024.

How much traffic does Service Road over Alley Spring Branch carry?

About 10 vehicles per day (2019 count).

How long is Service Road over Alley Spring Branch?

The structure is 91 ft (27.7 m) long with a longest span of 50 ft (15.2 m) and a deck 15 ft wide.

Who owns Service Road over Alley Spring Branch?

It is owned by the National Park Service.