US Bridges

Road 13 over Ash Slough

Poor

Madera County, California · Int Ave 25 1/2 · Structure no. 41C0127

Built
1965
60 years old
Condition
Poor
inspected March 2023
Type
Box Beam or Girders - Single or Spread
Steel
Length
282 ft
7 main spans
Daily traffic
316
1979 count
Owner
County
County Highway Agency

About this bridge

Road 13 over Ash Slough is a steel box beam or girders - single or spread carrying Road 13 over Ash Slough in Madera County, California. It was built in 1965, so it is 60 years old, older 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 316 vehicles a day, roughly 13% of them trucks, projected to reach 927 by 2041. The structure is 282 ft (86 m) long and 28 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesRoad 13
CrossesAsh Slough
LocationInt Ave 25 1/2
RouteCounty Highway 0
CountyMadera County
StateCalifornia
Coordinates37.12033, -120.31084
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.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating37.1 US tons
Inventory rating22.2 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialSteel
DeckConcrete, cast-in-place
Main spans7
Design loadUnknown
Structure length282 ft (86 m)
Longest span40 ft (12.2 m)
Deck width28 ft (8.6 m)
Roadway width28 ft (8.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic316 (1979)
Projected traffic927 by 2041
Trucks13%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed3.7 mi (6 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$1.2 million (2018 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Road 13 over Ash Slough built?

It was built in 1965, making it 60 years old in 2025.

What condition is Road 13 over Ash Slough 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 March 2023.

How much traffic does Road 13 over Ash Slough carry?

About 316 vehicles per day (1979 count), of which roughly 13% are trucks.

How long is Road 13 over Ash Slough?

The structure is 282 ft (86 m) long with a longest span of 40 ft (12.2 m) and a deck 28 ft wide.

Who owns Road 13 over Ash Slough?

It is owned by the County Highway Agency.