US Bridges

Summit Ave over Hillside

Fair

Marin County, California · 1.4 MI Intrx Lovell Ave · Structure no. 27C0052

Built
1980
45 years old
Condition
Fair
inspected July 2023
Type
Slab
Wood or Timber
Length
72 ft
4 main spans
Daily traffic
257
2004 count
Owner
City
City or Municipal Highway Agency

About this bridge

Summit Ave over Hillside is a wood or timber slab carrying Summit Ave over Hillside in Marin County, California. It was built in 1980, so it is 45 years old, younger 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 257 vehicles a day, roughly 3% of them trucks, projected to reach 436 by 2041. The structure is 72 ft (21.9 m) long and 18 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesSummit Ave
CrossesHillside
Location1.4 MI Intrx Lovell Ave
RouteCity Street 0
CountyMarin County
StateCalifornia
Coordinates37.91697, -122.5602
Functional classUrban Local

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.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionJuly 2023
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 geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment6: Equal to present minimum criteria
Operating rating25.4 US tons
Inventory rating18.5 US tons

Structure

Structure typeSlab
MaterialWood or Timber
DeckWood or timber
Main spans4
Design loadUnknown
Structure length72 ft (21.9 m)
Longest span18 ft (5.4 m)
Deck width18 ft (5.4 m)
Roadway width15 ft (4.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic257 (2004)
Projected traffic436 by 2041
Trucks3%
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway and pedestrian
CrossesOther
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Summit Ave over Hillside built?

It was built in 1980, making it 45 years old in 2025.

What condition is Summit Ave over Hillside 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 July 2023.

How much traffic does Summit Ave over Hillside carry?

About 257 vehicles per day (2004 count), of which roughly 3% are trucks.

How long is Summit Ave over Hillside?

The structure is 72 ft (21.9 m) long with a longest span of 18 ft (5.4 m) and a deck 18 ft wide.

Who owns Summit Ave over Hillside?

It is owned by the City or Municipal Highway Agency.