US Bridges

Southard Av(cr 21) over Marsh Bog Brook

Fair

Monmouth County, New Jersey · 1.08 MI E of CR 524 Alt · Structure no. 130HL63

Built
1975
50 years old
Condition
Fair
inspected April 2023
Type
Slab
Prestressed Concrete
Length
38 ft
1 main span
Daily traffic
3,682
2023 count
Owner
County
County Highway Agency

About this bridge

Southard Av(cr 21) over Marsh Bog Brook is a prestressed concrete slab carrying Southard Av(cr 21) over Marsh Bog Brook in Monmouth County, New Jersey. It was built in 1975, so it is 50 years old, younger than the New Jersey average of 58.5 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 3,682 vehicles a day, roughly 3% of them trucks, projected to reach 4,418 by 2043. The structure is 38 ft (11.6 m) long and 38 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesSouthard Av(cr 21)
CrossesMarsh Bog Brook
Location1.08 MI E of CR 524 Alt
RouteCounty Highway 21
CountyMonmouth County
StateNew Jersey
Coordinates40.19, -74.17698
Functional classUrban 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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating38 US tons
Inventory rating23 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, precast panels
Main spans1
Design loadUnknown
Structure length38 ft (11.6 m)
Longest span35 ft (10.7 m)
Deck width38 ft (11.6 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic3,682 (2023)
Projected traffic4,418 by 2043
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
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$1.4 million (2019 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was Southard Av(cr 21) over Marsh Bog Brook built?

It was built in 1975, making it 50 years old in 2025.

What condition is Southard Av(cr 21) over Marsh Bog Brook 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 2023.

How much traffic does Southard Av(cr 21) over Marsh Bog Brook carry?

About 3,682 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is Southard Av(cr 21) over Marsh Bog Brook?

The structure is 38 ft (11.6 m) long with a longest span of 35 ft (10.7 m) and a deck 38 ft wide.

Who owns Southard Av(cr 21) over Marsh Bog Brook?

It is owned by the County Highway Agency.