US Bridges

County RD 20 over Gum Spring CR

Fair

Iron County, Missouri · S 5 T 34 N R 3 E · Structure no. 28372

Built
1922
103 years old
Condition
Fair
inspected February 2025
Type
Arch - Deck
Concrete
Length
43 ft
1 main span
Daily traffic
200
2023 count
Owner
County
County Highway Agency

About this bridge

County RD 20 over Gum Spring CR is a concrete arch - deck carrying County RD 20 over Gum Spring CR in Iron County, Missouri. It was built in 1922, so it is 103 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 200 vehicles a day, roughly 10% of them trucks, projected to reach 240 by 2043. The structure is 43 ft (13.1 m) long and 21 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

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CarriesCounty RD 20
CrossesGum Spring CR
LocationS 5 T 34 N R 3 E
RouteCounty Highway 173
CountyIron County
StateMissouri
Coordinates37.6871, -90.7343
Functional classRural Local

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.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionFebruary 2025
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment4: Meets minimum tolerable limits to be left in place as is
Operating rating98.2 US tons
Inventory rating55.6 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadOther
Structure length43 ft (13.1 m)
Longest span40 ft (12.2 m)
Deck width21 ft (6.4 m)
Roadway width18 ft (5.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic200 (2023)
Projected traffic240 by 2043
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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$249,000 (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was County RD 20 over Gum Spring CR built?

It was built in 1922, making it 103 years old in 2025.

What condition is County RD 20 over Gum Spring CR 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 February 2025.

How much traffic does County RD 20 over Gum Spring CR carry?

About 200 vehicles per day (2023 count), of which roughly 10% are trucks.

How long is County RD 20 over Gum Spring CR?

The structure is 43 ft (13.1 m) long with a longest span of 40 ft (12.2 m) and a deck 21 ft wide.

Who owns County RD 20 over Gum Spring CR?

It is owned by the County Highway Agency.