US Bridges

Mill Road over I 90;MILL Road Ic

Poor

Shoshone County, Idaho · 0.4 W. Mullan · Structure no. 000000000030960

Built
1963
62 years old
Condition
Poor
inspected June 2024
Type
Tee Beam
Concrete
Length
240 ft
6 main spans
Daily traffic
110
2023 count
Owner
State
State Highway Agency

About this bridge

Mill Road over I 90;MILL Road Ic is a concrete tee beam carrying Mill Road over I 90;MILL Road Ic in Shoshone 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 110 vehicles a day, projected to reach 165 by 2042. The structure is 240 ft (73.2 m) long and 33 ft wide.

Location

Open in Google Maps
CarriesMill Road
CrossesI 90;MILL Road Ic
Location0.4 W. Mullan
RouteCounty Highway 0
CountyShoshone County
StateIdaho
Coordinates47.46606, -115.81306
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJune 2024
Inspection intervalevery 12 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating48 US tons
Inventory rating29 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans6
Design loadHS 20
Structure length240 ft (73.2 m)
Longest span41 ft (12.5 m)
Deck width33 ft (10 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic110 (2023)
Projected traffic165 by 2042
Trucks0%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesOverpass structure at an interchange
CrossesHighway and waterway
Detour if closed—
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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$2.4 million (2020 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Mill Road over I 90;MILL Road Ic built?

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

What condition is Mill Road over I 90;MILL Road Ic in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in June 2024.

How much traffic does Mill Road over I 90;MILL Road Ic carry?

About 110 vehicles per day (2023 count).

How long is Mill Road over I 90;MILL Road Ic?

The structure is 240 ft (73.2 m) long with a longest span of 41 ft (12.5 m) and a deck 33 ft wide.

Who owns Mill Road over I 90;MILL Road Ic?

It is owned by the State Highway Agency.