US Bridges

Hirschdale RD over UP RR BNSF RY & AMTRAK

Poor

Nevada County, California · 2.5 MI S of Boca · Structure no. 17C0046

Built
1926
99 years old
Condition
Poor
inspected August 2024
Type
Tee Beam
Concrete
Length
173 ft
4 main spans
Daily traffic
70
2014 count
Owner
County
County Highway Agency

About this bridge

Hirschdale RD over UP RR BNSF RY & AMTRAK is a concrete tee beam carrying Hirschdale RD over UP RR BNSF RY & AMTRAK in Nevada County, California. It was built in 1926, so it is 99 years old, older than the California average of 54.8 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 70 vehicles a day, roughly 5% of them trucks, projected to reach 275 by 2042. The structure is 173 ft (52.7 m) long and 26 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesHirschdale RD
CrossesUP RR BNSF RY & AMTRAK
Location2.5 MI S of Boca
RouteCounty Highway 0
CountyNevada County
StateCalifornia
Coordinates39.36699, -120.07281
Functional classRural Major Collector

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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment6: Equal to present minimum criteria
Operating rating35.7 US tons
Inventory rating24.7 US tons

Structure

Structure typeTee Beam
MaterialConcrete
DeckConcrete, cast-in-place
Main spans4
Design loadH 15
Structure length173 ft (52.7 m)
Longest span57 ft (17.4 m)
Deck width26 ft (7.9 m)
Roadway width21 ft (6.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic70 (2014)
Projected traffic275 by 2042
Trucks5%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesRailroad
Detour if closed5 mi (8 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$697,000 (2021 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Hirschdale RD over UP RR BNSF RY & AMTRAK built?

It was built in 1926, making it 99 years old in 2025.

What condition is Hirschdale RD over UP RR BNSF RY & AMTRAK 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 August 2024.

How much traffic does Hirschdale RD over UP RR BNSF RY & AMTRAK carry?

About 70 vehicles per day (2014 count), of which roughly 5% are trucks.

How long is Hirschdale RD over UP RR BNSF RY & AMTRAK?

The structure is 173 ft (52.7 m) long with a longest span of 57 ft (17.4 m) and a deck 26 ft wide.

Who owns Hirschdale RD over UP RR BNSF RY & AMTRAK?

It is owned by the County Highway Agency.