US Bridges

I 580 NB over Mill ST

Fair

Washoe County, Nevada · Reno · Structure no. I1252

Built
1977
48 years old, rebuilt 2018
Condition
Fair
inspected May 2024
Type
Box Beam or Girders - Multiple
Steel
Length
193 ft
1 main span
Daily traffic
81,000
2021 count
Owner
State
State Highway Agency

About this bridge

I 580 NB over Mill ST is a steel box beam or girders - multiple carrying I 580 NB over Mill ST in Washoe County, Nevada. It was built in 1977 and reconstructed in 2018, so it is 48 years old, older than the Nevada average of 36.4 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 81,000 vehicles a day, roughly 7% of them trucks, projected to reach 209,700 by 2040. The structure is 193 ft (58.8 m) long and 104 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesI 580 NB
CrossesMill ST
LocationReno
RouteInterstate 580
CountyWashoe County
StateNevada
Coordinates39.51979, -119.78332
Functional classUrban Principal Arterial - Interstate

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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment9: Superior to present desirable criteria
Operating rating110.1 US tons
Inventory rating60.1 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20 + Mod
Structure length193 ft (58.8 m)
Longest span187 ft (57 m)
Deck width104 ft (31.8 m)
Roadway width101 ft (30.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic81,000 (2021)
Projected traffic209,700 by 2040
Trucks7%
Lanes on structure7
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed0.6 mi (1 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$3.2 million
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 580 NB over Mill ST built?

It was built in 1977, making it 48 years old in 2025. It was reconstructed in 2018.

What condition is I 580 NB over Mill ST 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 May 2024.

How much traffic does I 580 NB over Mill ST carry?

About 81,000 vehicles per day (2021 count), of which roughly 7% are trucks.

How long is I 580 NB over Mill ST?

The structure is 193 ft (58.8 m) long with a longest span of 187 ft (57 m) and a deck 104 ft wide.

Who owns I 580 NB over Mill ST?

It is owned by the State Highway Agency.