US Bridges

INTERSTATE-91 NB over Muddy River

Fair

New Haven County, Connecticut · .8 MI So of Route 40 · Structure no. 03104

Built
1965
60 years old
Condition
Fair
inspected January 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
90 ft
1 main span
Daily traffic
55,750
2015 count
Owner
State
State Highway Agency

About this bridge

INTERSTATE-91 NB over Muddy River is a steel stringer/multi-beam or girder carrying INTERSTATE-91 NB over Muddy River in New Haven County, Connecticut. It was built in 1965, so it is 60 years old, older than the Connecticut average of 56.7 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 55,750 vehicles a day, roughly 9% of them trucks, projected to reach 82,839 by 2035. The structure is 90 ft (27.4 m) long and 68 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesINTERSTATE-91 NB
CrossesMuddy River
Location.8 MI So of Route 40
RouteInterstate 91
CountyNew Haven County
StateConnecticut
Coordinates41.36382, -72.86875
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJanuary 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour within limits of footing or piles
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating87 US tons
Inventory rating52 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length90 ft (27.4 m)
Longest span86 ft (26.2 m)
Deck width68 ft (20.6 m)
Roadway width64 ft (19.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic55,750 (2015)
Projected traffic82,839 by 2035
Trucks9%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 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—
NavigationNo navigation control on waterway

Frequently asked questions

When was INTERSTATE-91 NB over Muddy River built?

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

What condition is INTERSTATE-91 NB over Muddy River 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 January 2023.

How much traffic does INTERSTATE-91 NB over Muddy River carry?

About 55,750 vehicles per day (2015 count), of which roughly 9% are trucks.

How long is INTERSTATE-91 NB over Muddy River?

The structure is 90 ft (27.4 m) long with a longest span of 86 ft (26.2 m) and a deck 68 ft wide.

Who owns INTERSTATE-91 NB over Muddy River?

It is owned by the State Highway Agency.