US Bridges

4th Avenue over San Mateo Creek

Fair

San Mateo County, California · 4th Ave @ SR 101 · Structure no. 35C0176

Built
1998
27 years old
Condition
Fair
inspected April 2024
Type
Slab
Concrete Continuous
Length
69 ft
3 main spans
Daily traffic
7,500
2015 count
Owner
City
City or Municipal Highway Agency

About this bridge

4th Avenue over San Mateo Creek is a concrete continuous slab carrying 4th Avenue over San Mateo Creek in San Mateo County, California. It was built in 1998, so it is 27 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 7,500 vehicles a day, roughly 5% of them trucks, projected to reach 10,831 by 2044. The structure is 69 ft (21.1 m) long and 45 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
Carries4th Avenue
CrossesSan Mateo Creek
Location4th Ave @ SR 101
RouteCity Street 0
CountySan Mateo County
StateCalifornia
Coordinates37.56985, -122.31462
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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length69 ft (21.1 m)
Longest span34 ft (10.4 m)
Deck width45 ft (13.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic7,500 (2015)
Projected traffic10,831 by 2044
Trucks5%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was 4th Avenue over San Mateo Creek built?

It was built in 1998, making it 27 years old in 2025.

What condition is 4th Avenue over San Mateo 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 April 2024.

How much traffic does 4th Avenue over San Mateo Creek carry?

About 7,500 vehicles per day (2015 count), of which roughly 5% are trucks.

How long is 4th Avenue over San Mateo Creek?

The structure is 69 ft (21.1 m) long with a longest span of 34 ft (10.4 m) and a deck 45 ft wide.

Who owns 4th Avenue over San Mateo Creek?

It is owned by the City or Municipal Highway Agency.