US Bridges

I 15B ;broadway ST over Porter Canal

Fair

Bonneville County, Idaho · In Idaho Falls;broadway · Structure no. 000000000012110

Built
1987
38 years old
Condition
Fair
inspected March 2023
Type
Frame
Concrete
Length
24 ft
1 main span
Daily traffic
18,000
2023 count
Owner
State
State Highway Agency

About this bridge

I 15B ;broadway ST over Porter Canal is a concrete frame carrying I 15B ;broadway ST over Porter Canal in Bonneville County, Idaho. It was built in 1987, so it is 38 years old, younger than the Idaho average of 45.3 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 18,000 vehicles a day, roughly 2% of them trucks, projected to reach 27,000 by 2042. The structure is 24 ft (7.3 m) long and 104 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 15B ;broadway ST
CrossesPorter Canal
LocationIn Idaho Falls;broadway
RouteInterstate 15
CountyBonneville County
StateIdaho
Coordinates43.49389, -112.04661
Functional classUrban Other Principal 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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
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 inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating110.1 US tons
Inventory rating70 US tons

Structure

Structure typeFrame
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 25 or greater
Structure length24 ft (7.3 m)
Longest span24 ft (7.3 m)
Deck width104 ft (31.7 m)
Roadway width88 ft (26.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,000 (2023)
Projected traffic27,000 by 2042
Trucks2%
Lanes on structure7
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$1.2 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I 15B ;broadway ST over Porter Canal built?

It was built in 1987, making it 38 years old in 2025.

What condition is I 15B ;broadway ST over Porter Canal 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 March 2023.

How much traffic does I 15B ;broadway ST over Porter Canal carry?

About 18,000 vehicles per day (2023 count), of which roughly 2% are trucks.

How long is I 15B ;broadway ST over Porter Canal?

The structure is 24 ft (7.3 m) long with a longest span of 24 ft (7.3 m) and a deck 104 ft wide.

Who owns I 15B ;broadway ST over Porter Canal?

It is owned by the State Highway Agency.