Structure 4094 · Colleton County, SC

S-351/ashton RD over Willow Swamp

Carries S-351/ashton RD over Willow Swamp, 21.3 Mi NW Walterboro.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 8 of 9.

How ratings work
Decksets the rating8/9 · Very Good
Superstructuresets the rating8/9 · Very Good
Substructuresets the rating8/9 · Very Good
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT40 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 8/9Substructure 8/9

40 ft end to end. Lengths and the car 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 box-beam bridge.

Built201610 years old
Length40.0 ft12.2 m
Daily traffic175counted 2023
Last inspectedFebruary 2025every 24 months

Location

StateSouth Carolina
CountyColleton
Location21.3 Mi NW Walterboro
CarriesS-351/ashton RD
CrossesWillow Swamp
Coordinates33.06509, -80.97918

Physical Characteristics

MaterialPrestressed Concrete
DesignBox Beam - Multiple
Total Length40.0 ft (12.2 m)
Max Span40.0 ft (12.2 m)
Deck Width36.1 ft (11 m)
Deck Area134.2 sq m
Main Spans1
Year Built2016

Traffic

Avg Daily Traffic175 (2023)
Truck Traffic5%
Lanes On Bridge2

Inspection & Ownership

Last InspectionFebruary 2025
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceHistorical significance is not determined
Scour Critical8 — Stable, low risk
Structure Number000000000004094

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.

Nearby Bridges