US Bridges

ST 1 A/Sb over Other Relief & Ped Walkw

Fair

Suffolk County, Massachusetts · .16 KM N of Callahan Tun · Structure no. B162353A0DOTNBI

Built
1951
74 years old, rebuilt 2005
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
694 ft
10 main spans
Daily traffic
43,178
2023 count
Owner
State
State Highway Agency

About this bridge

ST 1 A/Sb over Other Relief & Ped Walkw is a steel stringer/multi-beam or girder carrying ST 1 A/Sb over Other Relief & Ped Walkw in Suffolk County, Massachusetts. It was built in 1951 and reconstructed in 2005, 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 43,178 vehicles a day, roughly 4% of them trucks, projected to reach 65,067 by 2031. The structure is 694 ft (211.5 m) long and 46 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesST 1 A/Sb
CrossesOther Relief & Ped Walkw
Location.16 KM N of Callahan Tun
RouteState Highway 1A
CountySuffolk County
StateMassachusetts
Coordinates42.37262, -71.03352
Functional classUrban Other Principal 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
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 inspectionNovember 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 geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71.4 US tons
Inventory rating42.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans10
Design loadHS 20
Structure length694 ft (211.5 m)
Longest span74 ft (22.6 m)
Deck width46 ft (13.9 m)
Roadway width41 ft (12.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic43,178 (2023)
Projected traffic65,067 by 2031
Trucks4%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
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$28.7 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was ST 1 A/Sb over Other Relief & Ped Walkw built?

It was built in 1951, making it 74 years old in 2025. It was reconstructed in 2005.

What condition is ST 1 A/Sb over Other Relief & Ped Walkw 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 November 2024.

How much traffic does ST 1 A/Sb over Other Relief & Ped Walkw carry?

About 43,178 vehicles per day (2023 count), of which roughly 4% are trucks.

How long is ST 1 A/Sb over Other Relief & Ped Walkw?

The structure is 694 ft (211.5 m) long with a longest span of 74 ft (22.6 m) and a deck 46 ft wide.

Who owns ST 1 A/Sb over Other Relief & Ped Walkw?

It is owned by the State Highway Agency.