Structure 506 · Southeast Fairbanks County, AK

Alaska Highway over Tok River

Carries Alaska Highway over Tok River, Mile Point 85.2.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure at 8 of 9.

How ratings work
Decksets the rating8/9 · Very Good
Superstructuresets the rating8/9 · Very Good
Substructure9/9 · Excellent
Channelnot part of overall8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT360 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9 · sets the ratingSuperstructure 8/9 · sets the ratingSubstructure 9/9

360 ft end to end, longest span 120 ft: about 5 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 tee-beam bridge.

Built20197 years old
Length359.9 ft109.7 m
Daily traffic400counted 2020
Last inspectedJuly 2024every 24 months

Location

StateAlaska
CountySoutheast Fairbanks
LocationMile Point 85.2
CarriesAlaska Highway
CrossesTok River
Coordinates63.32499, -142.83609

Physical Characteristics

MaterialPrestressed Concrete
DesignTee Beam
Total Length359.9 ft (109.7 m)
Max Span120.1 ft (36.6 m)
Deck Width43.0 ft (13.1 m)
Deck Area1437.1 sq m
Main Spans3
Year Built2019

Traffic

Avg Daily Traffic400 (2020)
Truck Traffic22%
Lanes On Bridge2

Inspection & Ownership

Last InspectionJuly 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour Critical8 — Stable, low risk
Structure Number0506

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.