US Bridges

Cispus Rd. over Siler Cr.

Fair

Lewis County, Washington · 0.03 NW RD 70301 · Structure no. 083676000000000

Built
1952
73 years old
Condition
Fair
inspected January 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
31 ft
1 main span
Daily traffic
254
2022 count
Owner
County
County Highway Agency

About this bridge

Cispus Rd. over Siler Cr. is a concrete stringer/multi-beam or girder carrying Cispus Rd. over Siler Cr. in Lewis County, Washington. It was built in 1952, so it is 73 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 254 vehicles a day, roughly 29% of them trucks, projected to reach 459 by 2042. The structure is 31 ft (9.4 m) long and 26 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesCispus Rd.
CrossesSiler Cr.
Location0.03 NW RD 70301
RouteCounty Highway 70700
CountyLewis County
StateWashington
Coordinates46.50431, -121.92558
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65 US tons
Inventory rating38.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length31 ft (9.4 m)
Longest span27 ft (8.2 m)
Deck width26 ft (7.8 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic254 (2022)
Projected traffic459 by 2042
Trucks29%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed5 mi (8 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 proposedOther structural work, including hydraulic replacements
Estimated improvement cost$456,000 (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Cispus Rd. over Siler Cr. built?

It was built in 1952, making it 73 years old in 2025.

What condition is Cispus Rd. over Siler Cr. 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 Cispus Rd. over Siler Cr. carry?

About 254 vehicles per day (2022 count), of which roughly 29% are trucks.

How long is Cispus Rd. over Siler Cr.?

The structure is 31 ft (9.4 m) long with a longest span of 27 ft (8.2 m) and a deck 26 ft wide.

Who owns Cispus Rd. over Siler Cr.?

It is owned by the County Highway Agency.