US Bridges

Donner Pass RD over Donner Summit

Fair

Nevada County, California · 2.0 MI W Donner Lake · Structure no. 17C0052

Built
1925
100 years old, rebuilt 1996
Condition
Fair
inspected August 2024
Type
Arch - Deck
Concrete
Length
241 ft
1 main span
Daily traffic
552
2014 count
Owner
County
County Highway Agency

About this bridge

Donner Pass RD over Donner Summit is a concrete arch - deck carrying Donner Pass RD over Donner Summit in Nevada County, California. It was built in 1925 and reconstructed in 1996, so it is 100 years old, older than the California average of 54.8 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 552 vehicles a day, roughly 10% of them trucks, projected to reach 998 by 2046. The structure is 241 ft (73.5 m) long and 27 ft wide. If it were closed, the detour would be 8.7 mi (14 km).

Location

Open in Google Maps
CarriesDonner Pass RD
CrossesDonner Summit
Location2.0 MI W Donner Lake
RouteCounty Highway 0
CountyNevada County
StateCalifornia
Coordinates39.31975, -120.31939
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Last inspectionAugust 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 geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating64.9 US tons
Inventory rating39 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1 (+3 approach)
Design loadH 15
Structure length241 ft (73.5 m)
Longest span117 ft (35.7 m)
Deck width27 ft (8.1 m)
Roadway width24 ft (7.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic552 (2014)
Projected traffic998 by 2046
Trucks10%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesOther
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Donner Pass RD over Donner Summit built?

It was built in 1925, making it 100 years old in 2025. It was reconstructed in 1996.

What condition is Donner Pass RD over Donner Summit 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 August 2024.

How much traffic does Donner Pass RD over Donner Summit carry?

About 552 vehicles per day (2014 count), of which roughly 10% are trucks.

How long is Donner Pass RD over Donner Summit?

The structure is 241 ft (73.5 m) long with a longest span of 117 ft (35.7 m) and a deck 27 ft wide.

Who owns Donner Pass RD over Donner Summit?

It is owned by the County Highway Agency.