US Bridges

ST 1 a over HWY Saratga ST & U Trn

Fair

Suffolk County, Massachusetts · 1.7 KM N of Callahan Tun · Structure no. B1623639YDOTNBI

Built
1951
74 years old, rebuilt 1977
Condition
Fair
inspected March 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
811 ft
10 main spans
Daily traffic
86,897
2023 count
Owner
State
State Highway Agency

About this bridge

ST 1 a over HWY Saratga ST & U Trn is a steel stringer/multi-beam or girder carrying ST 1 a over HWY Saratga ST & U Trn in Suffolk County, Massachusetts. It was built in 1951 and reconstructed in 1977, so it is 74 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 86,897 vehicles a day, roughly 7% of them trucks, projected to reach 86,862 by 2032. The structure is 811 ft (247.2 m) long and 86 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesST 1 a
CrossesHWY Saratga ST & U Trn
Location1.7 KM N of Callahan Tun
RouteState Highway 1A
CountySuffolk County
StateMassachusetts
Coordinates42.38155, -71.02323
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
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 inspectionMarch 2023
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 geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating68.6 US tons
Inventory rating41.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans10
Design loadHS 20
Structure length811 ft (247.2 m)
Longest span111 ft (33.7 m)
Deck width86 ft (26.1 m)
Roadway width77 ft (23.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic86,897 (2023)
Projected traffic86,862 by 2032
Trucks7%
Lanes on structure5
Traffic directionTwo-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

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$63 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was ST 1 a over HWY Saratga ST & U Trn built?

It was built in 1951, making it 74 years old in 2025. It was reconstructed in 1977.

What condition is ST 1 a over HWY Saratga ST & U Trn 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 March 2023.

How much traffic does ST 1 a over HWY Saratga ST & U Trn carry?

About 86,897 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is ST 1 a over HWY Saratga ST & U Trn?

The structure is 811 ft (247.2 m) long with a longest span of 111 ft (33.7 m) and a deck 86 ft wide.

Who owns ST 1 a over HWY Saratga ST & U Trn?

It is owned by the State Highway Agency.