US Bridges

I 93 /US1/ST3 over HWY Conley ST

Fair

Suffolk County, Massachusetts · 6.6 KM S of JCT I90&I93 · Structure no. B162643DCDOTNBI

Built
1955
70 years old, rebuilt 1984
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
118 ft
3 main spans
Daily traffic
193,593
2023 count
Owner
State
State Highway Agency

About this bridge

I 93 /US1/ST3 over HWY Conley ST is a steel stringer/multi-beam or girder carrying I 93 /US1/ST3 over HWY Conley ST in Suffolk County, Massachusetts. It was built in 1955 and reconstructed in 1984, so it is 70 years old, older than the Massachusetts average of 63.8 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 193,593 vehicles a day, roughly 7% of them trucks, projected to reach 331,969 by 2031. The structure is 118 ft (36 m) long and 117 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 93 /US1/ST3
CrossesHWY Conley ST
Location6.6 KM S of JCT I90&I93
RouteInterstate 93
CountySuffolk County
StateMassachusetts
Coordinates42.29326, -71.04476
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating66.1 US tons
Inventory rating41 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length118 ft (36 m)
Longest span51 ft (15.5 m)
Deck width117 ft (35.8 m)
Roadway width110 ft (33.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic193,593 (2023)
Projected traffic331,969 by 2031
Trucks7%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 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 proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$12.9 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 93 /US1/ST3 over HWY Conley ST built?

It was built in 1955, making it 70 years old in 2025. It was reconstructed in 1984.

What condition is I 93 /US1/ST3 over HWY Conley ST 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 2024.

How much traffic does I 93 /US1/ST3 over HWY Conley ST carry?

About 193,593 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is I 93 /US1/ST3 over HWY Conley ST?

The structure is 118 ft (36 m) long with a longest span of 51 ft (15.5 m) and a deck 117 ft wide.

Who owns I 93 /US1/ST3 over HWY Conley ST?

It is owned by the State Highway Agency.