San Mateo County, CA

393 public highway bridges

San Mateo County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, San Mateo County, California contains 393 public highway bridges. Roughly 16.3% are rated “Good,” 31.3% “Fair,” and 5.3% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.

Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.

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

393

Total Bridges

16.3%

Good

31.3%

Fair

5.3%

Poor Condition

Condition Distribution

Good

16.3% (64)

Fair

31.3% (123)

Poor

5.3% (21)

All Bridges (393)

Sort:

SAND HILL ROAD (S)

Over: INTERSTATE 280

04-SM-280-R1.56, San Mateo, CA

Built 1969 ADT: 101,000

SAND HILL ROAD (N)

Over: INTERSTATE 280

04-SM-280-R1.61, San Mateo, CA

Built 1969 ADT: 101,000

I-280 SOUTHBOUND

Over: ALPINE RD & LOS TRANCOS

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

Built 1969 ADT: 3,500

I-280 NORTHBOUND

Over: ALPINE RD & LOS TRANCOS

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

Built 1969 ADT: 3,500

CALTRAIN & UP RR

Over: U.S. HIGHWAY 101

04-SM-101-3.05-MLP, San Mateo, CA

Built 1931 ADT: 199,000

MANOR DRIVE

Over: STATE ROUTE 1

04-SM-001-R45.12-PFA, San Mateo, CA

Built 1965 ADT: 32,500

THIRD AVENUE

Over: US HIGHWAY 101

04-SM-101-13.46-SM, San Mateo, CA

Built 1953 ADT: 20,000

FASHION ISLAND BL

Over: US HIGHWAY 101

04-SM-101-11.90-SM, San Mateo, CA

Built 1985 ADT: 236,000

HOLLY STREET

Over: US HIGHWAY 101

04-SM-101-8.40, San Mateo, CA

Built 1954 ADT: 20,000

BUNKER HILL DRIVE

Over: INTERSTATE 280

04-SM-280-R12.32, San Mateo, CA

Built 1969 ADT: 111,000

W380-N280 CONNECTR

Over: N280 ON-RAMP COLLECTOR

04-SM-380-T4.71, San Mateo, CA

Built 1971 ADT: 15,000

S101-S84 CONNECTOR

Over: UP RR SPUR & VETERANS BL

04-SM-101-5.50-RDWC, San Mateo, CA

Built 1972 ADT: 22,600

SR 84 (MARSH RD)

Over: US HIGHWAY 101

04-SM-084-R25.81-MLP, San Mateo, CA

Built 1998 ADT: 199,000

N101-S84 CONNECTOR

Over: WOODSIDE ROAD

04-SM-101-5.39-RDWC, San Mateo, CA

Built 1958 ADT: 1,210

U.S. HIGHWAY 101

Over: SR 84 (WOODSIDE ROAD)

04-SM-101-5.39-RDWC, San Mateo, CA

Built 1958 ADT: 43,000

MAPLE STREET

Over: US HIGHWAY 101

04-SM-101-5.88-RDWC, San Mateo, CA

Built 1958 ADT: 195,000

MILLBRAE AVENUE

Over: U.S. HIGHWAY 101

04-SM-101-17.95-MLBR, San Mateo, CA

Built 1947 ADT: 226,000

STATE ROUTE 84

Over: SR 82 - EL CAMINO REAL

04-SM-084-24.68-RDWC, San Mateo, CA

Built 1965 ADT: 35,250

US HIGHWAY 101 SB

Over: CALTRAIN,UP RR,GRAND,ONR

04-SM-101-21.92-SSF, San Mateo, CA

Built 1948 ADT: 18,600

US HIGHWAY 101 NB

Over: CALTRAIN,UP RR,GRAND,ONR

04-SM-101-21.92-SSF, San Mateo, CA

Built 1948 ADT: 95,100

UNIVERSITY AVE NB

Over: US HIGHWAY 101

04-SM-101-0.88-EAPA, San Mateo, CA

Built 1958 ADT: 199,000

RALSTON AVENUE

Over: US HIGHWAY 101

04-SM-101-9.55-BMT, San Mateo, CA

Built 1974 ADT: 195,000

INTERSTATE 280 SB

Over: HICKEY BOULEVARD

04-SM-280-R24.20-DLC, San Mateo, CA

Built 1967 ADT: 22,200

INTERSTATE 280 NB

Over: HICKEY BOULEVARD

04-SM-280-R24.20-DLC, San Mateo, CA

Built 1967 ADT: 22,200

U.S. HIGHWAY 101

Over: AIRPORT BOULEVARD

04-SM-101-21.69-SSF, San Mateo, CA

Built 1947 ADT: 9,280

WHIPPLE AVENUE

Over: US HIGHWAY 101

04-SM-101-6.62-RDWC, San Mateo, CA

Built 1958 ADT: 195,000

N101-BAYSHORE OFF

Over: US HIGHWAY 101

04-SM-101-23.39-SSF, San Mateo, CA

Built 1957 ADT: 219,000

EAST HILLSDALE BL

Over: US HIGHWAY 101

04-SM-101-11.15-SM, San Mateo, CA

Built 1954 ADT: 15,000

UNIVERSITY AVE SB

Over: US HIGHWAY 101

04-SM-101-0.89-EAPA, San Mateo, CA

Built 1958 ADT: 199,000

WB STATE ROUTE 92

Over: STATE ROUTE 82

04-SM-092-R11.19-SM, San Mateo, CA

Built 1963 ADT: 32,000

EB STATE ROUTE 92

Over: STATE ROUTE 82

04-SM-092-R11.19-SM, San Mateo, CA

Built 1963 ADT: 32,000

WB STATE ROUTE 92

Over: CALTRAIN,UP RR,PACIFIC,

04-SM-092-R11.38-SM, San Mateo, CA

Built 1963 ADT: 300

EB STATE ROUTE 92

Over: CALTRAIN,UP RR,PACIFIC,

04-SM-092-R11.38-SM, San Mateo, CA

Built 1963 ADT: 300

WB STATE ROUTE 92

Over: DELAWARE STREET

04-SM-092-R11.61-SM, San Mateo, CA

Built 1963 ADT: 400

EB STATE ROUTE 92

Over: DELAWARE STREET

04-SM-092-R11.61-SM, San Mateo, CA

Built 1963 ADT: 300

STATE ROUTE 92

Over: PALM AVENUE

04-SM-092-R11.30-SM, San Mateo, CA

Built 1963 ADT: 6,460

ALAMEDA DE LAS PUL

Over: STATE ROUTE 92

04-SM-092-R10.56-SM, San Mateo, CA

Built 1963 ADT: 72,000

STATE ROUTE 92

Over: WEST HILLSDALE BLVD

04-SM-092-R9.38-SM, San Mateo, CA

Built 1967 ADT: 33,000

SHARP PARK ROAD

Over: STATE ROUTE 1

04-SM-001-R43.46-PFA, San Mateo, CA

Built 1965 ADT: 32,500

JOHN DALY BLVD

Over: INTERSTATE 280, SR 1

04-SM-280-M27.17L-DLC, San Mateo, CA

Built 1965 ADT: 141,000

S280-JUNIPERO SERR

Over: INTERSTATE 280

04-SM-280-M27.20L-DLC, San Mateo, CA

Built 1965 ADT: 141,000

JUNIPERO SERRA-NB1

Over: INTERSTATE 280

04-SM-001-R48.38-DLC, San Mateo, CA

Built 1965 ADT: 141,000

ST CHARLES AVENUE

Over: INTERSTATE 280

04-SM-280-M27.41L-DLC, San Mateo, CA

Built 1965 ADT: 141,000

INTERSTATE 280

Over: SOUTHGATE AVENUE

04-SM-280-R25.04-DLC, San Mateo, CA

Built 1967 ADT: 11,000

N280-S1 CONNECTOR

Over: I 280, SR 1, & CONNS

04-SM-280-R25.26-DLC, San Mateo, CA

Built 1967 ADT: 74,000

STATE ROUTE 1 NB

Over: INTERSTATE 280

04-SM-001-R47.76-DLC, San Mateo, CA

Built 1967 ADT: 207,000

SAN PEDRO ROAD

Over: INTERSTATE 280

04-SM-280-R25.78-DLC, San Mateo, CA

Built 1965 ADT: 221,000

JUNIPERO SERRA BL

Over: INTERSTATE 280

04-SM-280-R26.04-DLC, San Mateo, CA

Built 1965 ADT: 207,000

SCHOOL STREET

Over: INTERSTATE 280

04-SM-280-R26.35-DLC, San Mateo, CA

Built 1965 ADT: 207,000

JUNIPERO SERRA BLV

Over: INTERSTATE 280

04-SM-280-R26.50-DLC, San Mateo, CA

Built 1965 ADT: 207,000

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

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Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

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Compiled by PlainBridges, Independent data publisher

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