US Bridges

SR 77 over Washboard Wash

Fair

Navajo County, Arizona · 18.3 MI N JCT SR 277 · Structure no. 00198

Built
1938
87 years old
Condition
Fair
inspected June 2023
Type
Slab
Concrete Continuous
Length
101 ft
4 main spans
Daily traffic
3,684
2021 count
Owner
State
State Highway Agency

About this bridge

SR 77 over Washboard Wash is a concrete continuous slab carrying SR 77 over Washboard Wash in Navajo County, Arizona. It was built in 1938, so it is 87 years old, older than the Arizona average of 47.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 5 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 3,684 vehicles a day, roughly 18% of them trucks, projected to reach 3,694 by 2041. The structure is 101 ft (30.8 m) long and 31 ft wide. If it were closed, the detour would be 34.8 mi (56 km).

Location

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CarriesSR 77
CrossesWashboard Wash
Location18.3 MI N JCT SR 277
RouteState Highway 77
CountyNavajo County
StateArizona
Coordinates34.7718, -110.12777
Functional classRural Principal Arterial - Other

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating52 US tons
Inventory rating31 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length101 ft (30.8 m)
Longest span25 ft (7.6 m)
Deck width31 ft (9.4 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,684 (2021)
Projected traffic3,694 by 2041
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed34.8 mi (56 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1,000 (2023 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was SR 77 over Washboard Wash built?

It was built in 1938, making it 87 years old in 2025.

What condition is SR 77 over Washboard Wash 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 June 2023.

How much traffic does SR 77 over Washboard Wash carry?

About 3,684 vehicles per day (2021 count), of which roughly 18% are trucks.

How long is SR 77 over Washboard Wash?

The structure is 101 ft (30.8 m) long with a longest span of 25 ft (7.6 m) and a deck 31 ft wide.

Who owns SR 77 over Washboard Wash?

It is owned by the State Highway Agency.