San Mateo County, CA

393 public highway bridges

San Mateo County Bridge Snapshot

San Mateo County, California contains 393 public highway bridges in the FHWA National Bridge Inventory. Roughly 16.3% are rated “Good,” 31.3% “Fair,” 5.3% “Poor,” and 5.3% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in CA are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

393
Total Bridges
16.3%
Good
5.3%
Poor
5.3%
Structurally Deficient

Condition Distribution

Good
16.3% (64)
Fair
31.3% (123)
Poor
5.3% (21)
SD
5.3% (21)

All Bridges (393)

INTERSTATE 280 NB

Fair

Over: CRYSTAL SPRINGS OFF-RAMP

04-SM-280-R20.04-SBR, San Mateo, CA

Built 1967 Load: 52.5 t ADT: 49,500

NORTH ACCESS RD

Fair

Over: SAN BRUNO CHANNEL

EAST OF AIRPORT BLVD, San Mateo, CA

Built 1986 Load: 56.4 t ADT: 9,494

PESCADERO RD

Fair

Over: PESCADERO CREEK

3 MI E BUTANO CUTT-OFF, San Mateo, CA

Built 1937 Load: 57.3 t ADT: 620

BEACH PARK BLVD

Fair

Over: FOSTER CITY LAGOON

0.1 MI E EDGEWATER BLVD, San Mateo, CA

Built 1975 Load: 57.3 t ADT: 9,750

W380-N101 CONNECTR

Fair

Over: NORTH CHANNEL

04-SM-380-6.48-SBR, San Mateo, CA

Built 1976 Load: 57.7 t ADT: 1,700

PESCADERO RD

Fair

Over: PESCADERO CREEK

2 MI E BUTANO CUTOFF, San Mateo, CA

Built 1937 Load: 61.6 t ADT: 720

SAND HILL RD

Fair

Over: BEAR GULCH CREEK

SOUTH WHISKEY HILL RD, San Mateo, CA

Built 1950 Load: 97.2 t ADT: 7,137

STATE ROUTE 84

Fair

Over: LA HONDA CREEK

04-SM-084-9.67, San Mateo, CA

Built 1954 Load: 99.9 t ADT: 2,900

NORTH B STREET

Good

Over: SAN MATEO CREEK

BALDWIN AVE @ NORTH B ST, San Mateo, CA

Built 1924 Load: 14.9 t ADT: 2,790

CRYSTAL SPRINGS RD

Good

Over: SAN MATEO CREEK

N EL CERRITO AVE, San Mateo, CA

Built 1904 Load: 15.2 t ADT: 10,000

DELAWARE ST

Good

Over: SAN MATEO CREEK

SOUTH OF CYPRESS AVE, San Mateo, CA

Built 1910 Load: 15.2 t ADT: 8,530

N CLAREMONT

Good

Over: SAN MATEO CREEK

NORTH OF 1ST ST, San Mateo, CA

Built 1920 Load: 15.9 t ADT: 1,830

OLD COUNTY RD

Good

Over: PULGAS CREEK

SOUTH COMMERCIAL ST, San Mateo, CA

Built 1920 Load: 16.2 t ADT: 7,000

FREMONT ST

Good

Over: SAN MATEO CREEK

2ND AVE & FREMONT ST, San Mateo, CA

Built 1920 Load: 16.8 t ADT: 2,890

SIERRA DRIVE

Good

Over: SAN MATEO CREEK

EL CERRITO AVE, San Mateo, CA

Built 1930 Load: 16.8 t ADT: 1,000

KINGS MOUNTAIN RD

Good

Over: WEST UNION CREEK

0.05 MI E TRIPP RD, San Mateo, CA

Built 1905 Load: 17.2 t ADT: 2,075

CANYON ROAD

Good

Over: SLIDE

1 MI NE OF CLOVERDALE RD, San Mateo, CA

Built 2000 Load: 21.4 t ADT: 120

NIMITZ DRIVE

Good

Over: FORK DRIVE

1300 SNEATH LN LN, SAN BR, San Mateo, CA

Built 1940 Load: 21.8 t ADT: 10

STATE ROUTE 84

Good

Over: EL CORTE DE MADERA CREEK

04-SM-084-3.92, San Mateo, CA

Built 1954 Load: 22.7 t ADT: 1,400

U.S. HIGHWAY 101

Good

Over: SAN MATEO CREEK

04-SM-101-13.44-SM, San Mateo, CA

Built 1928 Load: 24.0 t ADT: 236,000

U.S. HIGHWAY 101

Good

Over: BELMONT CREEK

04-SM-101-9.11-BMT, San Mateo, CA

Built 1930 Load: 24.3 t ADT: 195,000

INDUSTRIAL WAY

Good

Over: BELMONT CREEK

SOUTH HARBOR BLVD, San Mateo, CA

Built 1950 Load: 24.3 t ADT: 4,592

MARINE PKWY

Good

Over: BELMONT SLOUGH

EAST OF S.H. 101, San Mateo, CA

Built 1968 Load: 24.3 t ADT: 8,200

DELAWARE ST

Good

Over: FIESTA CHANNEL

0.3 MI S OF SH 92, San Mateo, CA

Built 1953 Load: 24.3 t ADT: 14,280

MARSH RD

Good

Over: MARSH SLOUGH

MARSH RD AT ROLISON, San Mateo, CA

Built 1960 Load: 24.3 t ADT: 5,300

ROAD-1 SOUTH

Good

Over: PEDESTRIAN WALKWAY

TERMINAL 3 - AREA F, San Mateo, CA

Built 1973 Load: 24.3 t ADT: 12,930

STATE PARK RD

Good

Over: PESCADERO CREEK

PORTOLA STATE PARK, San Mateo, CA

Built 2009 Load: 24.3 t ADT: 6

UNIVERSITY AVE

Good

Over: SAN FRANCISQUITO CREEK

0.01 MI S WOODLAND AVE, San Mateo, CA

Built 1925 Load: 24.6 t ADT: 24,200

STATE ROUTE 84

Good

Over: SAN GREGORIO CREEK

04-SM-084-7.55, San Mateo, CA

Built 1957 Load: 25.9 t ADT: 1,400

I-280 SB ONRAMP

Good

Over: LOS TRANCOS CREEK

04-SM-280-R0.01, San Mateo, CA

Built 1969 Load: 27.2 t ADT: 2,100

STAGE RD

Good

Over: SAN GREGORIO CREEK

0.1 MI S OF S.H. 84, San Mateo, CA

Built 1981 Load: 29.2 t ADT: 272

WILLOWBROOK DR

Good

Over: CORTE MADERA CREEK

0.2 MI S PORTOLA DR, San Mateo, CA

Built 1989 Load: 29.2 t ADT: 5,000

STATE ROUTE 1

Good

Over: GAZOS CREEK

04-SM-001-5.73, San Mateo, CA

Built 1958 Load: 30.1 t ADT: 4,400

STATE ROUTE 84

Good

Over: LA HONDA CREEK

04-SM-084-8.10, San Mateo, CA

Built 1957 Load: 30.1 t ADT: 1,400

3RD AVE-N101 ON RP

Good

Over: SAN MATEO CREEK

04-SM-101-13.44-SM, San Mateo, CA

Built 2004 Load: 32.4 t ADT: 15,000

N101-3RD AV OFFRMP

Good

Over: SAN MATEO CREEK

04-SM-101-13.44-SM, San Mateo, CA

Built 2004 Load: 32.4 t ADT: 20,000

U.S. HIGHWAY 101

Good

Over: PULGAS CREEK

04-SM-101-7.66-SCAR, San Mateo, CA

Built 2001 Load: 32.4 t ADT: 195,000

S101-3RD AVE OFFRP

Good

Over: SAN MATEO CREEK

04-SM-101-13.45-SM, San Mateo, CA

Built 1996 Load: 32.4 t ADT: 14,400

STATE ROUTE 1 SB

Good

Over: PILARCITOS CREEK

04-SM-001-28.92-HMBY, San Mateo, CA

Built 1954 Load: 32.4 t ADT: 14,750

STATE ROUTE 1 NB

Good

Over: PILARCITOS CREEK

04-SM-001-28.92-HMBY, San Mateo, CA

Built 1954 Load: 32.4 t ADT: 14,750

STATE ROUTE 1

Good

Over: LAKESHIRE DRIVE

04-SM-001-R46.86-DLC, San Mateo, CA

Built 1972 Load: 32.4 t ADT: 65,000

S280-SAN BRUNO OFF

Good

Over: INTERSTATE 380 (FUTURE)

04-SM-280-R20.98-SBR, San Mateo, CA

Built 1973 Load: 32.4 t ADT: 5,785

U.S. HIGHWAY 101

Good

Over: NORTH CHANNEL

04-SM-101-R20.63, San Mateo, CA

Built 1976 Load: 32.4 t ADT: 188,000

STATE ROUTE 84

Good

Over: PEDESTRIAN WALKWAY

04-SM-084-R27.62-MLP, San Mateo, CA

Built 1983 Load: 32.4 t ADT: 27,500

U.S. HIGHWAY 101

Good

Over: OYSTER POINT DRAIN

04-SM-101-22.90-SSF, San Mateo, CA

Built 1995 Load: 32.4 t ADT: 196,000

INTERSTATE 280

Good

Over: HILLSIDE

04-SM-280-R21.55, San Mateo, CA

Built 1994 Load: 32.4 t ADT: 101,000

STATE ROUTE 1

Good

Over: DEVIL SLIDE

04-SM-001-R39.93-PFA, San Mateo, CA

Built 2009 Load: 32.4 t ADT: 14,500

STATE ROUTE 1

Good

Over: DEVIL SLIDE

04-SM-001-R39.93-PFA, San Mateo, CA

Built 2009 Load: 32.4 t ADT: 14,500

US 101,W&E BAYSHR

Good

Over: SAN FRANCISQUITO CREEK

04-SM-101-0.01-PA, San Mateo, CA

Built 2018 Load: 32.4 t ADT: 225,800

STATE ROUTE 1

Good

Over: SAN PEDRO CREEK

04-SM-001-40.83, San Mateo, CA

Built 2015 Load: 32.4 t ADT: 14,500

Read our methodology — how this data is sourced, computed, and verified.

Related

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial