US Bridges

State Route 1 over Denniston Creek

Fair

San Mateo County, California · 04-SM-001-33.30-HMBY · Structure no. 35 0319

Built
1990
35 years old
Condition
Fair
inspected October 2022
Type
Culvert
Concrete Continuous
Length
27 ft
2 main spans
Daily traffic
15,600
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 1 over Denniston Creek is a concrete continuous culvert carrying State Route 1 over Denniston Creek in San Mateo County, California. It was built in 1990, so it is 35 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 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 15,600 vehicles a day, projected to reach 35,400 by 2040. The structure is 27 ft (8.2 m) long and 92 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesState Route 1
CrossesDenniston Creek
Location04-SM-001-33.30-HMBY
RouteState Highway 1
CountySan Mateo County
StateCalifornia
Coordinates37.50984, -122.48788
Functional classUrban Other Principal 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 protection8 Very GoodNo problems noted.
Culvert6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2022
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry9: Superior to present desirable criteria
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadUnknown
Structure length27 ft (8.2 m)
Longest span12 ft (3.7 m)
Deck width92 ft (27.9 m)
Roadway width73 ft (22.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic15,600 (2009)
Projected traffic35,400 by 2040
Trucks0%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState 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 State Route 1 over Denniston Creek built?

It was built in 1990, making it 35 years old in 2025.

What condition is State Route 1 over Denniston 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 October 2022.

How much traffic does State Route 1 over Denniston Creek carry?

About 15,600 vehicles per day (2009 count).

How long is State Route 1 over Denniston Creek?

The structure is 27 ft (8.2 m) long with a longest span of 12 ft (3.7 m) and a deck 92 ft wide.

Who owns State Route 1 over Denniston Creek?

It is owned by the State Highway Agency.