US Bridges

Postma Road over Roza Canal

Fair

Yakima County, Washington · 00.17 E Walters RD · Structure no. 084385000000000

Built
1969
56 years old
Condition
Fair
inspected January 2023
Type
Channel Beam
Concrete
Length
41 ft
1 main span
Daily traffic
1,158
2021 count
Owner
County
County Highway Agency

About this bridge

Postma Road over Roza Canal is a concrete channel beam carrying Postma Road over Roza Canal in Yakima County, Washington. It was built in 1969, so it is 56 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.

It carries about 1,158 vehicles a day, roughly 5% of them trucks, projected to reach 1,264 by 2041. The structure is 41 ft (12.5 m) long and 34 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesPostma Road
CrossesRoza Canal
Location00.17 E Walters RD
RouteCounty Highway 40800
CountyYakima County
StateWashington
Coordinates46.56256, -120.35256
Functional classRural Minor 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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating39.7 US tons
Inventory rating30.3 US tons

Structure

Structure typeChannel Beam
MaterialConcrete
DeckOther
Main spans1
Design loadH 20
Structure length41 ft (12.5 m)
Longest span40 ft (12.2 m)
Deck width34 ft (10.3 m)
Roadway width32 ft (9.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,158 (2021)
Projected traffic1,264 by 2041
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 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$110,000
NavigationNo navigation control on waterway

Frequently asked questions

When was Postma Road over Roza Canal built?

It was built in 1969, making it 56 years old in 2025.

What condition is Postma Road over Roza 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 January 2023.

How much traffic does Postma Road over Roza Canal carry?

About 1,158 vehicles per day (2021 count), of which roughly 5% are trucks.

How long is Postma Road over Roza Canal?

The structure is 41 ft (12.5 m) long with a longest span of 40 ft (12.2 m) and a deck 34 ft wide.

Who owns Postma Road over Roza Canal?

It is owned by the County Highway Agency.