Structure 20779 · Miller County, MO

Swinging Br RD over Grand Auglaize

Carries Swinging Br RD over Grand Auglaize, S 36 T 39 N R 15 W.

Overall conditionPoor

Set by its lowest-rated component: Superstructure at 2 of 9.

How ratings work
Deck5/9 · Fair
Superstructuresets the rating2/9 · Critical
Substructure5/9 · Fair
Channelnot part of overall6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT500 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 5/9Superstructure 2/9 · sets the ratingSubstructure 5/9

500 ft end to end, longest span 414 ft: about 7 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a suspension bridge.

Built1920106 years old
Length500.0 ft152.4 m
Daily traffic250counted 2023
Last inspectedJanuary 2021every 24 months

Location

StateMissouri
CountyMiller
LocationS 36 T 39 N R 15 W
CarriesSwinging Br RD
CrossesGrand Auglaize
Coordinates38.07708, -92.52679

Physical Characteristics

MaterialSteel Continuous
DesignSuspension
Total Length500.0 ft (152.4 m)
Max Span414.0 ft (126.2 m)
Deck Width14.4 ft (4.4 m)
Deck Area670.6 sq m
Main Spans2
Year Built1920

Traffic

Avg Daily Traffic250 (2023)
Truck Traffic10%
Lanes On Bridge1

Inspection & Ownership

Last InspectionJanuary 2021
Inspection FrequencyEvery 24 months
OwnerCounty Highway Agency
Historical SignificanceBridge is on the National Register of Historic Places
Scour Critical8 — Stable, low risk
Structure Number20779

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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