US Bridges

Eagle Nest Lane over Hillside

Poor

Sonoma County, California · 0.2 MI N River RD · Structure no. 20C0360

Built
1930
95 years old
Condition
Poor
inspected March 2024
Type
Stringer/Multi-beam or Girder
Wood or Timber
Length
56 ft
3 main spans
Daily traffic
100
2011 count
Owner
County
County Highway Agency

About this bridge

Eagle Nest Lane over Hillside is a wood or timber stringer/multi-beam or girder carrying Eagle Nest Lane over Hillside in Sonoma County, California. It was built in 1930, so it is 95 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 100 vehicles a day, roughly 1% of them trucks, projected to reach 218 by 2042. The structure is 56 ft (17.1 m) long and 13 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesEagle Nest Lane
CrossesHillside
Location0.2 MI N River RD
RouteCounty Highway 0
CountySonoma County
StateCalifornia
Coordinates38.51955, -122.98136
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMarch 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 geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment3: Basically intolerable, requiring high priority of corrective action
Operating rating48.6 US tons
Inventory rating35.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialWood or Timber
DeckWood or timber
Main spans3
Design loadUnknown
Structure length56 ft (17.1 m)
Longest span19 ft (5.8 m)
Deck width13 ft (4 m)
Roadway width12 ft (3.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic100 (2011)
Projected traffic218 by 2042
Trucks1%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesOther
Detour if closed123.7 mi (199 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 proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$243,000 (2019 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Eagle Nest Lane over Hillside built?

It was built in 1930, making it 95 years old in 2025.

What condition is Eagle Nest Lane over Hillside 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 March 2024.

How much traffic does Eagle Nest Lane over Hillside carry?

About 100 vehicles per day (2011 count), of which roughly 1% are trucks.

How long is Eagle Nest Lane over Hillside?

The structure is 56 ft (17.1 m) long with a longest span of 19 ft (5.8 m) and a deck 13 ft wide.

Who owns Eagle Nest Lane over Hillside?

It is owned by the County Highway Agency.