US Bridges

Md 423 over Branch of Herring Bay

Fair

Anne Arundel County, Maryland · 2.44 Mile East of Md 2 · Structure no. 100000020068010

Built
1989
36 years old
Condition
Fair
inspected September 2023
Type
Slab
Prestressed Concrete
Length
46 ft
1 main span
Daily traffic
1,492
2023 count
Owner
State
State Highway Agency

About this bridge

Md 423 over Branch of Herring Bay is a prestressed concrete slab carrying Md 423 over Branch of Herring Bay in Anne Arundel County, Maryland. It was built in 1989, so it is 36 years old, younger than the Maryland average of 52.6 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 1,492 vehicles a day, roughly 8% of them trucks, projected to reach 1,942 by 2045. The structure is 46 ft (14 m) long and 31 ft wide. If it were closed, the detour would be 3.7 mi (6 km).

Location

Open in Google Maps
CarriesMd 423
CrossesBranch of Herring Bay
Location2.44 Mile East of Md 2
RouteState Highway 423
CountyAnne Arundel County
StateMaryland
Coordinates38.7482, -76.55751
Functional classRural Minor Collector

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.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionSeptember 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 geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66.5 US tons
Inventory rating40 US tons

Structure

Structure typeSlab
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length46 ft (14 m)
Longest span40 ft (12.2 m)
Deck width31 ft (9.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,492 (2023)
Projected traffic1,942 by 2045
Trucks8%
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

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Md 423 over Branch of Herring Bay built?

It was built in 1989, making it 36 years old in 2025.

What condition is Md 423 over Branch of Herring Bay 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 September 2023.

How much traffic does Md 423 over Branch of Herring Bay carry?

About 1,492 vehicles per day (2023 count), of which roughly 8% are trucks.

How long is Md 423 over Branch of Herring Bay?

The structure is 46 ft (14 m) long with a longest span of 40 ft (12.2 m) and a deck 31 ft wide.

Who owns Md 423 over Branch of Herring Bay?

It is owned by the State Highway Agency.