US Bridges

State Route 74 over San Juan Canyon

Fair

Orange County, California · 12-ORA-074-13.29-SJCP · Structure no. 55 0064

Built
1929
96 years old
Condition
Fair
inspected August 2023
Type
Arch - Deck
Concrete
Length
180 ft
1 main span
Daily traffic
9,800
2014 count
Owner
State
State Highway Agency

About this bridge

State Route 74 over San Juan Canyon is a concrete arch - deck carrying State Route 74 over San Juan Canyon in Orange County, California. It was built in 1929, so it is 96 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 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 9,800 vehicles a day, roughly 7% of them trucks, projected to reach 13,400 by 2040. The structure is 180 ft (54.9 m) long and 25 ft wide. If it were closed, the detour would be 123.7 mi (199 km).

Location

Open in Google Maps
CarriesState Route 74
CrossesSan Juan Canyon
Location12-ORA-074-13.29-SJCP
RouteState Highway 74
CountyOrange County
StateCalifornia
Coordinates33.59039, -117.50196
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionAugust 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating30 US tons
Inventory rating17.9 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadUnknown
Structure length180 ft (54.9 m)
Longest span149 ft (45.4 m)
Deck width25 ft (7.7 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic9,800 (2014)
Projected traffic13,400 by 2040
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed123.7 mi (199 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible 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 74 over San Juan Canyon built?

It was built in 1929, making it 96 years old in 2025.

What condition is State Route 74 over San Juan Canyon 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 August 2023.

How much traffic does State Route 74 over San Juan Canyon carry?

About 9,800 vehicles per day (2014 count), of which roughly 7% are trucks.

How long is State Route 74 over San Juan Canyon?

The structure is 180 ft (54.9 m) long with a longest span of 149 ft (45.4 m) and a deck 25 ft wide.

Who owns State Route 74 over San Juan Canyon?

It is owned by the State Highway Agency.