US Bridges

Bayshore HWY over Mills Creek

Fair

San Mateo County, California · 0.5 MI N Airport Blvd · Structure no. 35C0104

Built
1950
75 years old
Condition
Fair
inspected May 2023
Type
Culvert
Concrete Continuous
Length
22 ft
2 main spans
Daily traffic
18,000
2020 count
Owner
City
City or Municipal Highway Agency

About this bridge

Bayshore HWY over Mills Creek is a concrete continuous culvert carrying Bayshore HWY over Mills Creek in San Mateo County, California. It was built in 1950, so it is 75 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 6 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 18,000 vehicles a day, roughly 10% of them trucks, projected to reach 21,519 by 2041. The structure is 22 ft (6.7 m) long and 76 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesBayshore HWY
CrossesMills Creek
Location0.5 MI N Airport Blvd
RouteCity Street 0
CountySan Mateo County
StateCalifornia
Coordinates37.59718, -122.36576
Functional classUrban Minor Arterial

Condition and inspection

Fair

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

ComponentRatingMeaning
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Culvert6 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 evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating44.6 US tons
Inventory rating26.8 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length22 ft (6.7 m)
Longest span10 ft (3.2 m)
Deck width76 ft (23.3 m)
Roadway width65 ft (19.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,000 (2020)
Projected traffic21,519 by 2041
Trucks10%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed3.7 mi (6 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 Bayshore HWY over Mills Creek built?

It was built in 1950, making it 75 years old in 2025.

What condition is Bayshore HWY over Mills 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 Bayshore HWY over Mills Creek carry?

About 18,000 vehicles per day (2020 count), of which roughly 10% are trucks.

How long is Bayshore HWY over Mills Creek?

The structure is 22 ft (6.7 m) long with a longest span of 10 ft (3.2 m) and a deck 76 ft wide.

Who owns Bayshore HWY over Mills Creek?

It is owned by the City or Municipal Highway Agency.