US Bridges

STP8393;FRANKLIN B over Phyllis Canal

Fair

Canyon County, Idaho · In Nampa;franklin Blvd. · Structure no. 000000000021865

Built
1963
62 years old
Condition
Fair
inspected February 2023
Type
Stringer/Multi-beam or Girder
Concrete
Length
30 ft
1 main span
Daily traffic
18,500
2023 count
Owner
City
City or Municipal Highway Agency

About this bridge

STP8393;FRANKLIN B over Phyllis Canal is a concrete stringer/multi-beam or girder carrying STP8393;FRANKLIN B over Phyllis Canal in Canyon County, Idaho. It was built in 1963, so it is 62 years old, older 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 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 18,500 vehicles a day, roughly 6% of them trucks, projected to reach 27,750 by 2042. The structure is 30 ft (9.1 m) long and 66 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesSTP8393;FRANKLIN B
CrossesPhyllis Canal
LocationIn Nampa;franklin Blvd.
RouteCity Street 8393
CountyCanyon County
StateIdaho
Coordinates43.58889, -116.55308
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionFebruary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating46 US tons
Inventory rating27 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length30 ft (9.1 m)
Longest span29 ft (8.8 m)
Deck width66 ft (20.1 m)
Roadway width64 ft (19.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,500 (2023)
Projected traffic27,750 by 2042
Trucks6%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$606,000 (2021 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was STP8393;FRANKLIN B over Phyllis Canal built?

It was built in 1963, making it 62 years old in 2025.

What condition is STP8393;FRANKLIN B over Phyllis 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 February 2023.

How much traffic does STP8393;FRANKLIN B over Phyllis Canal carry?

About 18,500 vehicles per day (2023 count), of which roughly 6% are trucks.

How long is STP8393;FRANKLIN B over Phyllis Canal?

The structure is 30 ft (9.1 m) long with a longest span of 29 ft (8.8 m) and a deck 66 ft wide.

Who owns STP8393;FRANKLIN B over Phyllis Canal?

It is owned by the City or Municipal Highway Agency.