US Bridges

SH 16 over Phyllis Canal

Good

Ada County, Idaho · 0.8 S 1.25 E Star Scl · Structure no. 000000000034010

Built
2014
11 years old
Condition
Good
inspected November 2023
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
45 ft
1 main span
Daily traffic
18,000
2023 count
Owner
State
State Highway Agency

About this bridge

SH 16 over Phyllis Canal is a prestressed concrete box beam or girders - multiple carrying SH 16 over Phyllis Canal in Ada County, Idaho. It was built in 2014, so it is 11 years old, younger than the Idaho average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 18,000 vehicles a day, roughly 9% of them trucks, projected to reach 27,000 by 2042. The structure is 45 ft (13.7 m) long and 164 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesSH 16
CrossesPhyllis Canal
Location0.8 S 1.25 E Star Scl
RouteState Highway 16
CountyAda County
StateIdaho
Coordinates43.66948, -116.4682
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure8 Very GoodNo problems noted.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionNovember 2023
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation8: Equal to present desirable criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating100 US tons
Inventory rating68.6 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHL 93
Structure length45 ft (13.7 m)
Longest span41 ft (12.5 m)
Deck width164 ft (50 m)
Roadway width85 ft (25.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,000 (2023)
Projected traffic27,000 by 2042
Trucks9%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was SH 16 over Phyllis Canal built?

It was built in 2014, making it 11 years old in 2025.

What condition is SH 16 over Phyllis Canal in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in November 2023.

How much traffic does SH 16 over Phyllis Canal carry?

About 18,000 vehicles per day (2023 count), of which roughly 9% are trucks.

How long is SH 16 over Phyllis Canal?

The structure is 45 ft (13.7 m) long with a longest span of 41 ft (12.5 m) and a deck 164 ft wide.

Who owns SH 16 over Phyllis Canal?

It is owned by the State Highway Agency.