US Bridges

Harmonica RD over UP RR

PoorPosted for load

Mercer County, Missouri · S 34 T 65 N R 24 W · Structure no. 17756

Built
1901
124 years old
Condition
Poor
inspected February 2024
Type
Girder and Floorbeam System
Steel
Length
211 ft
1 main span
Daily traffic
35
2024 count
Owner
County
County Highway Agency

About this bridge

Harmonica RD over UP RR is a steel girder and floorbeam system carrying Harmonica RD over UP RR in Mercer County, Missouri. It was built in 1901, so it is 124 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 35 vehicles a day, roughly 10% of them trucks, projected to reach 39 by 2044. The structure is 211 ft (64.3 m) long and 21 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesHarmonica RD
CrossesUP RR
LocationS 34 T 65 N R 24 W
RouteCounty Highway 0
CountyMercer County
StateMissouri
Coordinates40.38989, -93.58006
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
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourBridge not over waterway
Structural evaluation2: Basically intolerable, requiring high priority of replacement
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating17.9 US tons
Inventory rating10.9 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckWood or timber
Main spans1 (+8 approach)
Design loadOther
Structure length211 ft (64.3 m)
Longest span66 ft (20.1 m)
Deck width21 ft (6.4 m)
Roadway width20 ft (6.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic35 (2024)
Projected traffic39 by 2044
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed5 mi (8 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.4 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Harmonica RD over UP RR built?

It was built in 1901, making it 124 years old in 2025.

What condition is Harmonica RD over UP RR 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 February 2024.

How much traffic does Harmonica RD over UP RR carry?

About 35 vehicles per day (2024 count), of which roughly 10% are trucks.

How long is Harmonica RD over UP RR?

The structure is 211 ft (64.3 m) long with a longest span of 66 ft (20.1 m) and a deck 21 ft wide.

Who owns Harmonica RD over UP RR?

It is owned by the County Highway Agency.