US Bridges

Chil. Spur HWY 488 over Williamson River

Fair

Klamath County, Oregon · 000 MI from Chiloquin · Structure no. 21396 422 00457

Built
2011
14 years old
Condition
Fair
inspected July 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
118 ft
1 main span
Daily traffic
3,562
2022 count
Owner
State
State Highway Agency

About this bridge

Chil. Spur HWY 488 over Williamson River is a prestressed concrete box beam or girders - multiple carrying Chil. Spur HWY 488 over Williamson River in Klamath County, Oregon. It was built in 2011, so it is 14 years old, younger 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 3,562 vehicles a day, roughly 16% of them trucks, projected to reach 3,700 by 2042. The structure is 118 ft (36 m) long and 53 ft wide. If it were closed, the detour would be 2.5 mi (4 km).

Location

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CarriesChil. Spur HWY 488
CrossesWilliamson River
Location000 MI from Chiloquin
RouteState Highway 422
CountyKlamath County
StateOregon
Coordinates42.57771, -121.86579
Functional classRural Major 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
Deck8 Very GoodNo problems noted.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating58.2 US tons
Inventory rating45 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadHL 93
Structure length118 ft (36 m)
Longest span118 ft (36 m)
Deck width53 ft (16.2 m)
Roadway width36 ft (11 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,562 (2022)
Projected traffic3,700 by 2042
Trucks16%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed2.5 mi (4 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Chil. Spur HWY 488 over Williamson River built?

It was built in 2011, making it 14 years old in 2025.

What condition is Chil. Spur HWY 488 over Williamson River 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 July 2023.

How much traffic does Chil. Spur HWY 488 over Williamson River carry?

About 3,562 vehicles per day (2022 count), of which roughly 16% are trucks.

How long is Chil. Spur HWY 488 over Williamson River?

The structure is 118 ft (36 m) long with a longest span of 118 ft (36 m) and a deck 53 ft wide.

Who owns Chil. Spur HWY 488 over Williamson River?

It is owned by the State Highway Agency.