US Bridges

RTE 25 over Mill Creek

Fair

Suffolk County, New York · 5.0 MI NE of Southold · Structure no. 000000001060930

Built
1979
46 years old
Condition
Fair
inspected October 2024
Type
Box Beam or Girders - Multiple
Prestressed Concrete
Length
52 ft
1 main span
Daily traffic
10,635
2020 count
Owner
State
State Highway Agency

About this bridge

RTE 25 over Mill Creek is a prestressed concrete box beam or girders - multiple carrying RTE 25 over Mill Creek in Suffolk County, New York. It was built in 1979, so it is 46 years old, younger than the New York average of 53 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 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 10,635 vehicles a day, roughly 8% of them trucks, projected to reach 12,919 by 2041. The structure is 52 ft (15.8 m) long and 53 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

CarriesRTE 25
CrossesMill Creek
Location5.0 MI NE of Southold
RouteState Highway 25
Coordinates41.07866, -72.39783
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating59 US tons
Inventory rating27 US tons

Structure

MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length52 ft (15.8 m)
Longest span49 ft (14.9 m)
Deck width53 ft (16.2 m)
Roadway width44 ft (13.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic10,635 (2020)
Projected traffic12,919 by 2041
Trucks8%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.9 mi (3 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 proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$3.1 million (2024 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was RTE 25 over Mill Creek built?

It was built in 1979, making it 46 years old in 2025.

What condition is RTE 25 over Mill Creek 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 October 2024.

How much traffic does RTE 25 over Mill Creek carry?

About 10,635 vehicles per day (2020 count), of which roughly 8% are trucks.

How long is RTE 25 over Mill Creek?

The structure is 52 ft (15.8 m) long with a longest span of 49 ft (14.9 m) and a deck 53 ft wide.

Who owns RTE 25 over Mill Creek?

It is owned by the State Highway Agency.