US Bridges

Montezuma RD over San Geronimo Creek

Fair

Marin County, California · .03 MI S SR Frncs Drake B · Structure no. 27C0127

Built
1938
87 years old
Condition
Fair
inspected August 2023
Type
Culvert
Concrete Continuous
Length
33 ft
3 main spans
Daily traffic
50
1980 count
Owner
County
County Highway Agency

About this bridge

Montezuma RD over San Geronimo Creek is a concrete continuous culvert carrying Montezuma RD over San Geronimo Creek in Marin County, California. It was built in 1938, so it is 87 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 6 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 50 vehicles a day, projected to reach 163 by 2041. The structure is 33 ft (10.1 m) long and 31 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesMontezuma RD
CrossesSan Geronimo Creek
Location.03 MI S SR Frncs Drake B
RouteCounty Highway 0
CountyMarin County
StateCalifornia
Coordinates38.01469, -122.68889
Functional classRural 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
Channel and channel protection7 GoodSome minor problems.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry6: Equal to present minimum criteria
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30 US tons
Inventory rating17.9 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadUnknown
Structure length33 ft (10.1 m)
Longest span10 ft (3 m)
Deck width31 ft (9.4 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic50 (1980)
Projected traffic163 by 2041
Trucks—
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
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 proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Montezuma RD over San Geronimo Creek built?

It was built in 1938, making it 87 years old in 2025.

What condition is Montezuma RD over San Geronimo Creek 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 2023.

How much traffic does Montezuma RD over San Geronimo Creek carry?

About 50 vehicles per day (1980 count).

How long is Montezuma RD over San Geronimo Creek?

The structure is 33 ft (10.1 m) long with a longest span of 10 ft (3 m) and a deck 31 ft wide.

Who owns Montezuma RD over San Geronimo Creek?

It is owned by the County Highway Agency.