US Bridges

Smithson RD over Hiline Canal

FairPosted for load

Kittitas County, Washington · 00.85 NE Robbins RD · Structure no. 083488000000000

Built
1931
94 years old, rebuilt 1977
Condition
Fair
inspected October 2024
Type
Channel Beam
Concrete
Length
53 ft
1 main span
Daily traffic
24
2020 count
Owner
County
County Highway Agency

About this bridge

Smithson RD over Hiline Canal is a concrete channel beam carrying Smithson RD over Hiline Canal in Kittitas County, Washington. It was built in 1931 and reconstructed in 1977, so it is 94 years old, older than the Washington average of 49.8 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. Its operating status is: posted for load restriction.

It carries about 24 vehicles a day, roughly 35% of them trucks, projected to reach 63 by 2040. The structure is 53 ft (16.2 m) long and 30 ft wide. If it were closed, the detour would be 98.8 mi (159 km).

Location

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CarriesSmithson RD
CrossesHiline Canal
Location00.85 NE Robbins RD
RouteCounty Highway 33513
CountyKittitas County
StateWashington
Coordinates47.10797, -120.54986
Functional classRural Local

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating23 US tons
Inventory rating17 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckOther
Main spans1
Design loadHS 20
Structure length53 ft (16.2 m)
Longest span51 ft (15.5 m)
Deck width30 ft (9.1 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24 (2020)
Projected traffic63 by 2040
Trucks35%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed98.8 mi (159 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.3 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Smithson RD over Hiline Canal built?

It was built in 1931, making it 94 years old in 2025. It was reconstructed in 1977.

What condition is Smithson RD over Hiline Canal 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 October 2024.

How much traffic does Smithson RD over Hiline Canal carry?

About 24 vehicles per day (2020 count), of which roughly 35% are trucks.

How long is Smithson RD over Hiline Canal?

The structure is 53 ft (16.2 m) long with a longest span of 51 ft (15.5 m) and a deck 30 ft wide.

Who owns Smithson RD over Hiline Canal?

It is owned by the County Highway Agency.