US Bridges

8400600-0.59 over Mod

Fair

Ketchikan Gateway Borough, Alaska · Upper Carroll · Structure no. 100552000010645

Built
2007
18 years old
Condition
Fair
inspected July 2021
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
40 ft
1 main span
Daily traffic
2
2006 count
Owner
Federal
U.S. Forest Service

About this bridge

8400600-0.59 over Mod is a wood or timber stringer/multi-beam or girder carrying 8400600-0.59 over Mod in Ketchikan Gateway Borough, Alaska. It was built in 2007, so it is 18 years old, younger than the Alaska average of 35.9 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 2 vehicles a day, projected to reach 3 by 2045. The structure is 40 ft (12.2 m) long and 18 ft wide. If it were closed, the detour would be 98.2 mi (158 km).

Location

Open in Google Maps
Carries8400600-0.59
CrossesMod
LocationUpper Carroll
RouteFederal Lands Road 84006
CountyKetchikan Gateway Borough
StateAlaska
Coordinates55.6716, -131.3389
Functional classRural Local

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 protection7 GoodSome minor problems.
Last inspectionJuly 2021
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating87.2 US tons
Inventory rating67.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans1
Design loadOther
Structure length40 ft (12.2 m)
Longest span40 ft (12.2 m)
Deck width18 ft (5.5 m)
Roadway width16 ft (4.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2 (2006)
Projected traffic3 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 8400600-0.59 over Mod built?

It was built in 2007, making it 18 years old in 2025.

What condition is 8400600-0.59 over Mod 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 July 2021.

How much traffic does 8400600-0.59 over Mod carry?

About 2 vehicles per day (2006 count).

How long is 8400600-0.59 over Mod?

The structure is 40 ft (12.2 m) long with a longest span of 40 ft (12.2 m) and a deck 18 ft wide.

Who owns 8400600-0.59 over Mod?

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