Structure H220 · Navajo County, AZ

IRR BIA RTE 4 over Oraibi Wash

Carries IRR BIA RTE 4 over Oraibi Wash, 23 Km North Of HWY 264.

Overall conditionFair

Set by its lowest-rated component: Deck at 6 of 9.

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructure7/9 · Good
Substructure7/9 · Good
Channelnot part of overall5/9 · Fair
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT225 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9 · sets the ratingSuperstructure 7/9Substructure 7/9

225 ft end to end, longest span 76 ft: about 3 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built197947 years old
Length225.4 ft68.7 m
Daily traffic165counted 2024
Last inspectedDecember 2024every 24 months

Location

StateArizona
CountyNavajo
Location23 Km North Of HWY 264
CarriesIRR BIA RTE 4
CrossesOraibi Wash
Coordinates36.04056, -110.47658

Physical Characteristics

MaterialPrestressed Concrete Continuous
DesignStringer/Multi-beam
Total Length225.4 ft (68.7 m)
Max Span76.4 ft (23.3 m)
Deck Width41.0 ft (12.5 m)
Deck Area858.8 sq m
Main Spans3
Year Built1979

Traffic

Avg Daily Traffic165 (2024)
Truck Traffic7%
Lanes On Bridge2

Inspection & Ownership

Last InspectionDecember 2024
Inspection FrequencyEvery 24 months
OwnerBureau of Indian Affairs
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number00000000000H220

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.