US Bridges

SR 717 over Mill River

Fair

New Haven County, Connecticut · 0.3 MI E of Route 10 · Structure no. 01660

Built
1948
77 years old, rebuilt 1989
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
71 ft
2 main spans
Daily traffic
18,600
2015 count
Owner
State
State Highway Agency

About this bridge

SR 717 over Mill River is a steel stringer/multi-beam or girder carrying SR 717 over Mill River in New Haven County, Connecticut. It was built in 1948 and reconstructed in 1989, so it is 77 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 18,600 vehicles a day, roughly 3% of them trucks, projected to reach 27,638 by 2035. The structure is 71 ft (21.6 m) long and 45 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesSR 717
CrossesMill River
Location0.3 MI E of Route 10
RouteState Highway 717
CountyNew Haven County
StateConnecticut
Coordinates41.38285, -72.89642
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
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57 US tons
Inventory rating34 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans2
Design loadUnknown
Structure length71 ft (21.6 m)
Longest span33 ft (10.1 m)
Deck width45 ft (13.6 m)
Roadway width41 ft (12.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,600 (2015)
Projected traffic27,638 by 2035
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.2 mi (2 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 SR 717 over Mill River built?

It was built in 1948, making it 77 years old in 2025. It was reconstructed in 1989.

What condition is SR 717 over Mill 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 May 2023.

How much traffic does SR 717 over Mill River carry?

About 18,600 vehicles per day (2015 count), of which roughly 3% are trucks.

How long is SR 717 over Mill River?

The structure is 71 ft (21.6 m) long with a longest span of 33 ft (10.1 m) and a deck 45 ft wide.

Who owns SR 717 over Mill River?

It is owned by the State Highway Agency.