US Bridges

Thorne Road over Arroyo Seco River

Fair

Monterey County, California · 2 MI West of SR 101 · Structure no. 44C0183

Built
2010
15 years old
Condition
Fair
inspected April 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete Continuous
Length
600 ft
4 main spans
Daily traffic
1,200
2016 count
Owner
County
County Highway Agency

About this bridge

Thorne Road over Arroyo Seco River is a prestressed concrete continuous box beam or girders - multiple carrying Thorne Road over Arroyo Seco River in Monterey County, California. It was built in 2010, so it is 15 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 1,200 vehicles a day, roughly 1% of them trucks, projected to reach 1,041 by 2041. The structure is 600 ft (182.9 m) long and 43 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesThorne Road
CrossesArroyo Seco River
Location2 MI West of SR 101
RouteCounty Highway 0
CountyMonterey County
StateCalifornia
Coordinates36.32238, -121.29401
Functional classRural 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
Deck8 Very GoodNo problems noted.
Superstructure8 Very GoodNo problems noted.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection9 ExcellentNo problems noted.
Last inspectionApril 2024
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 adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59.6 US tons
Inventory rating35.7 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length600 ft (182.9 m)
Longest span150 ft (45.7 m)
Deck width43 ft (13.1 m)
Roadway width40 ft (12.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,200 (2016)
Projected traffic1,041 by 2041
Trucks1%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCounty Highway Agency
Maintained byCounty 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 Thorne Road over Arroyo Seco River built?

It was built in 2010, making it 15 years old in 2025.

What condition is Thorne Road over Arroyo Seco River 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 Thorne Road over Arroyo Seco River carry?

About 1,200 vehicles per day (2016 count), of which roughly 1% are trucks.

How long is Thorne Road over Arroyo Seco River?

The structure is 600 ft (182.9 m) long with a longest span of 150 ft (45.7 m) and a deck 43 ft wide.

Who owns Thorne Road over Arroyo Seco River?

It is owned by the County Highway Agency.