US Bridges

Irr:deering Road over Smith Creek

Fair

Northwest Arctic Borough, Alaska · Mile Point 25.7 · Structure no. 1098

Built
1979
46 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
116 ft
3 main spans
Daily traffic
18
2018 count
Owner
State
State Highway Agency

About this bridge

Irr:deering Road over Smith Creek is a steel stringer/multi-beam or girder carrying Irr:deering Road over Smith Creek in Northwest Arctic Borough, Alaska. It was built in 1979, so it is 46 years old, older 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 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 18 vehicles a day, roughly 6% of them trucks, projected to reach 40 by 2035. The structure is 116 ft (35.3 m) long and 15 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

CarriesIrr:deering Road
CrossesSmith Creek
LocationMile Point 25.7
RouteState Highway 180
StateAlaska
Coordinates66.07436, -162.72167
Functional classRural Minor Collector

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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating59.4 US tons
Inventory rating35.6 US tons

Structure

MaterialSteel
DeckWood or timber
Main spans3
Design loadHS 15
Structure length116 ft (35.3 m)
Longest span43 ft (13.1 m)
Deck width15 ft (4.6 m)
Roadway width14 ft (4.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18 (2018)
Projected traffic40 by 2035
Trucks6%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Irr:deering Road over Smith Creek built?

It was built in 1979, making it 46 years old in 2025.

What condition is Irr:deering Road over Smith Creek 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 August 2024.

How much traffic does Irr:deering Road over Smith Creek carry?

About 18 vehicles per day (2018 count), of which roughly 6% are trucks.

How long is Irr:deering Road over Smith Creek?

The structure is 116 ft (35.3 m) long with a longest span of 43 ft (13.1 m) and a deck 15 ft wide.

Who owns Irr:deering Road over Smith Creek?

It is owned by the State Highway Agency.