US Bridges

Miramontes ST over Arroyo Leon Creek

Fair

San Mateo County, California · 0.3 MI E of Main ST · Structure no. 35C0098

Built
1986
39 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
71 ft
1 main span
Daily traffic
310
2017 count
Owner
City
City or Municipal Highway Agency

About this bridge

Miramontes ST over Arroyo Leon Creek is a prestressed concrete stringer/multi-beam or girder carrying Miramontes ST over Arroyo Leon Creek in San Mateo County, California. It was built in 1986, so it is 39 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 310 vehicles a day, roughly 1% of them trucks, projected to reach 213 by 2040. The structure is 71 ft (21.6 m) long and 26 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

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CarriesMiramontes ST
CrossesArroyo Leon Creek
Location0.3 MI E of Main ST
RouteCity Street 0
CountySan Mateo County
StateCalifornia
Coordinates37.46231, -122.42675
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating62.2 US tons
Inventory rating41.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length71 ft (21.6 m)
Longest span66 ft (20.1 m)
Deck width26 ft (7.9 m)
Roadway width24 ft (7.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic310 (2017)
Projected traffic213 by 2040
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
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 Miramontes ST over Arroyo Leon Creek built?

It was built in 1986, making it 39 years old in 2025.

What condition is Miramontes ST over Arroyo Leon 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 Miramontes ST over Arroyo Leon Creek carry?

About 310 vehicles per day (2017 count), of which roughly 1% are trucks.

How long is Miramontes ST over Arroyo Leon Creek?

The structure is 71 ft (21.6 m) long with a longest span of 66 ft (20.1 m) and a deck 26 ft wide.

Who owns Miramontes ST over Arroyo Leon Creek?

It is owned by the City or Municipal Highway Agency.