US Bridges

ST 1 A/Sb over Other Relief

Good

Suffolk County, Massachusetts · Segment 2 · Structure no. B16589583DOTNBI

Built
1999
26 years old
Condition
Good
inspected September 2024
Type
Box Beam or Girders - Single or Spread
Prestressed Concrete Continuous
Length
465 ft
3 main spans
Daily traffic
22,241
2024 count
Owner
State
State Highway Agency

About this bridge

ST 1 A/Sb over Other Relief is a prestressed concrete continuous box beam or girders - single or spread carrying ST 1 A/Sb over Other Relief in Suffolk County, Massachusetts. It was built in 1999, so it is 26 years old, younger than the Massachusetts average of 63.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 22,241 vehicles a day, roughly 2% of them trucks. The structure is 465 ft (141.7 m) long and 26 ft wide.

CarriesST 1 A/Sb
CrossesOther Relief
LocationSegment 2
Coordinates42.37443, -71.03101
Functional classUrban Other Principal Arterial

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating86.6 US tons
Inventory rating45.4 US tons

Structure

MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length465 ft (141.7 m)
Longest span155 ft (47.2 m)
Deck width26 ft (7.9 m)
Roadway width22 ft (6.7 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic22,241 (2024)
Projected traffic—
Trucks2%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesPedestrian / bicycle
Detour if closed—
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$22.2 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

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

It was built in 1999, making it 26 years old in 2025.

What condition is ST 1 A/Sb over Other Relief in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in September 2024.

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

About 22,241 vehicles per day (2024 count), of which roughly 2% are trucks.

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

The structure is 465 ft (141.7 m) long with a longest span of 155 ft (47.2 m) and a deck 26 ft wide.

Who owns ST 1 A/Sb over Other Relief?

It is owned by the State Highway Agency.