US Bridges

Mountain Home RD over Bear Creek

Fair

San Mateo County, California · 0.3 MI S of S.H. 84 · Structure no. 35C0122

Built
1900
125 years old
Condition
Fair
inspected May 2023
Type
Arch - Deck
Concrete
Length
38 ft
1 main span
Daily traffic
500
2015 count
Owner
City
City or Municipal Highway Agency

About this bridge

Mountain Home RD over Bear Creek is a concrete arch - deck carrying Mountain Home RD over Bear Creek in San Mateo County, California. It was built in 1900, so it is 125 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 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 500 vehicles a day, roughly 1% of them trucks, projected to reach 417 by 2040. The structure is 38 ft (11.6 m) long and 21 ft wide. If it were closed, the detour would be 9.9 mi (16 km).

Location

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CarriesMountain Home RD
CrossesBear Creek
Location0.3 MI S of S.H. 84
RouteCity Street 0
CountySan Mateo County
StateCalifornia
Coordinates37.42659, -122.25339
Functional classRural Major Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating28.5 US tons
Inventory rating17.2 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans1
Design loadUnknown
Structure length38 ft (11.6 m)
Longest span34 ft (10.4 m)
Deck width21 ft (6.4 m)
Roadway width18 ft (5.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic500 (2015)
Projected traffic417 by 2040
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed9.9 mi (16 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

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

Frequently asked questions

When was Mountain Home RD over Bear Creek built?

It was built in 1900, making it 125 years old in 2025.

What condition is Mountain Home RD over Bear 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 May 2023.

How much traffic does Mountain Home RD over Bear Creek carry?

About 500 vehicles per day (2015 count), of which roughly 1% are trucks.

How long is Mountain Home RD over Bear Creek?

The structure is 38 ft (11.6 m) long with a longest span of 34 ft (10.4 m) and a deck 21 ft wide.

Who owns Mountain Home RD over Bear Creek?

It is owned by the City or Municipal Highway Agency.