US Bridges

21st SE over Shelton Ditch

Fair

Marion County, Oregon · 1000 Block · Structure no. 470430000

Built
1959
66 years old
Condition
Fair
inspected August 2023
Type
Tee Beam
Concrete
Length
51 ft
1 main span
Daily traffic
3,278
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

21st SE over Shelton Ditch is a concrete tee beam carrying 21st SE over Shelton Ditch in Marion County, Oregon. It was built in 1959, so it is 66 years old, older than the Oregon average of 49.9 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.

It carries about 3,278 vehicles a day, roughly 5% of them trucks, projected to reach 3,678 by 2025. The structure is 51 ft (15.5 m) long and 42 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
Carries21st SE
CrossesShelton Ditch
Location1000 Block
RouteCity Street C0000
CountyMarion County
StateOregon
Coordinates44.92691, -123.01881
Functional classUrban 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 inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating23.9 US tons
Inventory rating18.5 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length51 ft (15.5 m)
Longest span50 ft (15.2 m)
Deck width42 ft (12.8 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,278 (2020)
Projected traffic3,678 by 2025
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed0.6 mi (1 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 21st SE over Shelton Ditch built?

It was built in 1959, making it 66 years old in 2025.

What condition is 21st SE over Shelton Ditch 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 August 2023.

How much traffic does 21st SE over Shelton Ditch carry?

About 3,278 vehicles per day (2020 count), of which roughly 5% are trucks.

How long is 21st SE over Shelton Ditch?

The structure is 51 ft (15.5 m) long with a longest span of 50 ft (15.2 m) and a deck 42 ft wide.

Who owns 21st SE over Shelton Ditch?

It is owned by the City or Municipal Highway Agency.