US Bridges

Portage Glacier RD over Portage CR Overflow No 1

Fair

Anchorage Municipality, Alaska · Mile Point 3.2 · Structure no. 0403

Built
1965
60 years old
Condition
Fair
inspected June 2023
Type
Slab
Concrete
Length
83 ft
3 main spans
Daily traffic
920
2020 count
Owner
State
State Highway Agency

About this bridge

Portage Glacier RD over Portage CR Overflow No 1 is a concrete slab carrying Portage Glacier RD over Portage CR Overflow No 1 in Anchorage Municipality, Alaska. It was built in 1965, so it is 60 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 920 vehicles a day, roughly 12% of them trucks, projected to reach 1,310 by 2039. The structure is 83 ft (25.3 m) long and 34 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesPortage Glacier RD
CrossesPortage CR Overflow No 1
LocationMile Point 3.2
RouteState Highway 496
CountyAnchorage Municipality
StateAlaska
Coordinates60.79306, -148.90417
Functional classRural Minor Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
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 alignment8: Equal to present desirable criteria
Operating rating97.7 US tons
Inventory rating37.8 US tons

Structure

Structure typeSlab
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length83 ft (25.3 m)
Longest span27 ft (8.2 m)
Deck width34 ft (10.3 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic920 (2020)
Projected traffic1,310 by 2039
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemYes

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 Portage Glacier RD over Portage CR Overflow No 1 built?

It was built in 1965, making it 60 years old in 2025.

What condition is Portage Glacier RD over Portage CR Overflow No 1 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 June 2023.

How much traffic does Portage Glacier RD over Portage CR Overflow No 1 carry?

About 920 vehicles per day (2020 count), of which roughly 12% are trucks.

How long is Portage Glacier RD over Portage CR Overflow No 1?

The structure is 83 ft (25.3 m) long with a longest span of 27 ft (8.2 m) and a deck 34 ft wide.

Who owns Portage Glacier RD over Portage CR Overflow No 1?

It is owned by the State Highway Agency.