US Bridges

State Route 99 over Athlone Drain

Good

Merced County, California · 10-MER-099-6.49 · Structure no. 39 0247

Built
2015
10 years old
Condition
Good
inspected April 2024
Type
Culvert
Concrete Continuous
Length
22 ft
2 main spans
Daily traffic
39,000
2009 count
Owner
State
State Highway Agency

About this bridge

State Route 99 over Athlone Drain is a concrete continuous culvert carrying State Route 99 over Athlone Drain in Merced County, California. It was built in 2015, so it is 10 years old, younger than the California average of 54.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 39,000 vehicles a day, projected to reach 57,312 by 2046. The structure is 22 ft (6.7 m) long. If it were closed, the detour would be 8.7 mi (14 km).

CarriesState Route 99
CrossesAthlone Drain
Location10-MER-099-6.49
RouteState Highway 99
Coordinates37.22146, -120.37085
Functional classRural Principal Arterial - Other

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Channel and channel protection8 Very GoodNo problems noted.
Culvert7 GoodSome minor problems.
Last inspectionApril 2024
Inspection intervalevery 48 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: 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 typeCulvert
MaterialConcrete Continuous
DeckNot applicable
Main spans2
Design loadGreater than HL 93
Structure length22 ft (6.7 m)
Longest span10 ft (3 m)
Deck width0 ft (0 m)
Roadway width0 ft (0 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic39,000 (2009)
Projected traffic57,312 by 2046
Trucks0%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed8.7 mi (14 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

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—
NavigationNot applicable (no waterway)

Frequently asked questions

When was State Route 99 over Athlone Drain built?

It was built in 2015, making it 10 years old in 2025.

What condition is State Route 99 over Athlone Drain in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in April 2024.

How much traffic does State Route 99 over Athlone Drain carry?

About 39,000 vehicles per day (2009 count).

How long is State Route 99 over Athlone Drain?

The structure is 22 ft (6.7 m) long with a longest span of 10 ft (3 m).

Who owns State Route 99 over Athlone Drain?

It is owned by the State Highway Agency.