US Bridges

Main Road over Little Butano Creek

Poor

San Mateo County, California · Butano ST Prk 0.4 MI in · Structure no. 35P0005

Built
1980
45 years old
Condition
Poor
inspected April 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
53 ft
1 main span
Daily traffic
70
2018 count
Owner
State
State Park, Forest, or Reservation Agency

About this bridge

Main Road over Little Butano Creek is a steel stringer/multi-beam or girder carrying Main Road over Little Butano Creek in San Mateo County, California. It was built in 1980, so it is 45 years old, younger than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 70 vehicles a day, projected to reach 80 by 2042. The structure is 53 ft (16.2 m) long and 14 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesMain Road
CrossesLittle Butano Creek
LocationButano ST Prk 0.4 MI in
RouteState Lands Road 0
CountySan Mateo County
StateCalifornia
Coordinates37.20608, -122.33465
Functional classRural Local

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating37.1 US tons
Inventory rating22.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckWood or timber
Main spans1
Design loadUnknown
Structure length53 ft (16.2 m)
Longest span50 ft (15.2 m)
Deck width14 ft (4.4 m)
Roadway width12 ft (3.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic70 (2018)
Projected traffic80 by 2042
Trucks—
Lanes on structure1
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Park, Forest, or Reservation Agency
Maintained byState Park, Forest, or Reservation Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$270,000 (2017 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Main Road over Little Butano Creek built?

It was built in 1980, making it 45 years old in 2025.

What condition is Main Road over Little Butano Creek in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in April 2024.

How much traffic does Main Road over Little Butano Creek carry?

About 70 vehicles per day (2018 count).

How long is Main Road over Little Butano Creek?

The structure is 53 ft (16.2 m) long with a longest span of 50 ft (15.2 m) and a deck 14 ft wide.

Who owns Main Road over Little Butano Creek?

It is owned by the State Park, Forest, or Reservation Agency.