US Bridges

43506 over Log

Poor

Petersburg Census Area, Alaska · Tonka · Structure no. 100521000003090

Built
2002
23 years old
Condition
Poor
inspected August 2023
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
42 ft
1 main span
Daily traffic
5
2006 count
Owner
Federal
U.S. Forest Service

About this bridge

43506 over Log is a wood or timber stringer/multi-beam or girder carrying 43506 over Log in Petersburg Census Area, Alaska. It was built in 2002, so it is 23 years old, younger than the Alaska average of 35.9 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 5 vehicles a day, projected to reach 7 by 2045. The structure is 42 ft (12.8 m) long and 20 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Carries43506
CrossesLog
LocationTonka
RouteFederal Lands Road 43506
StateAlaska
Coordinates56.77151, -133.13702
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating34.6 US tons
Inventory rating26.8 US tons

Structure

MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadOther
Structure length42 ft (12.8 m)
Longest span39 ft (11.9 m)
Deck width20 ft (6.2 m)
Roadway width14 ft (4.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic5 (2006)
Projected traffic7 by 2045
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed98.2 mi (158 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerU.S. Forest Service
Maintained byU.S. Forest Service
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was 43506 over Log built?

It was built in 2002, making it 23 years old in 2025.

What condition is 43506 over Log in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2023.

How much traffic does 43506 over Log carry?

About 5 vehicles per day (2006 count).

How long is 43506 over Log?

The structure is 42 ft (12.8 m) long with a longest span of 39 ft (11.9 m) and a deck 20 ft wide.

Who owns 43506 over Log?

It is owned by the U.S. Forest Service.