US Bridges

State Route 1 over Olema Creek

Good

Marin County, California · 04-MRN-001-22.96 · Structure no. 27 0021

Built
1928
97 years old
Condition
Good
inspected May 2022
Type
Slab
Concrete Continuous
Length
54 ft
3 main spans
Daily traffic
2,500
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Olema Creek is a concrete continuous slab carrying State Route 1 over Olema Creek in Marin County, California. It was built in 1928, so it is 97 years old, older than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 2,500 vehicles a day, roughly 1% of them trucks, projected to reach 4,778 by 2039. The structure is 54 ft (16.5 m) long and 25 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesOlema Creek
Location04-MRN-001-22.96
RouteState Highway 1
CountyMarin County
StateCalifornia
Coordinates37.99903, -122.75575
Functional classRural Minor Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating65.4 US tons
Inventory rating39.2 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 15
Structure length54 ft (16.5 m)
Longest span16 ft (4.9 m)
Deck width25 ft (7.7 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,500 (2009)
Projected traffic4,778 by 2039
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.1 mi (13 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNot applicable (no waterway)

Frequently asked questions

When was State Route 1 over Olema Creek built?

It was built in 1928, making it 97 years old in 2025.

What condition is State Route 1 over Olema Creek in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in May 2022.

How much traffic does State Route 1 over Olema Creek carry?

About 2,500 vehicles per day (2009 count), of which roughly 1% are trucks.

How long is State Route 1 over Olema Creek?

The structure is 54 ft (16.5 m) long with a longest span of 16 ft (4.9 m) and a deck 25 ft wide.

Who owns State Route 1 over Olema Creek?

It is owned by the State Highway Agency.