US Bridges

I 93 NB over I 93 Sb/Austn St/Mbta

Good

Suffolk County, Massachusetts · I93/US1 Interchange · Structure no. B166008YYDOTNBI

Built
2002
23 years old
Condition
Good
inspected September 2022
Type
Box Beam or Girders - Multiple
Steel Continuous
Length
532 ft
4 main spans
Daily traffic
36,462
2021 count
Owner
State
State Highway Agency

About this bridge

I 93 NB over I 93 Sb/Austn St/Mbta is a steel continuous box beam or girders - multiple carrying I 93 NB over I 93 Sb/Austn St/Mbta in Suffolk County, Massachusetts. It was built in 2002, so it is 23 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 36,462 vehicles a day, roughly 9% of them trucks, projected to reach 74,227 by 2031. The structure is 532 ft (162.3 m) long and 72 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

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CarriesI 93 NB
CrossesI 93 Sb/Austn St/Mbta
LocationI93/US1 Interchange
RouteInterstate 93
CountySuffolk County
StateMassachusetts
Coordinates42.37337, -71.06972
Functional classUrban Principal Arterial - Interstate

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 2022
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating74.3 US tons
Inventory rating44.5 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 25 or greater
Structure length532 ft (162.3 m)
Longest span148 ft (45.1 m)
Deck width72 ft (21.8 m)
Roadway width68 ft (20.6 m)
Vertical clearance over deck18 ft (5.4 m)

Traffic and service

Average daily traffic36,462 (2021)
Projected traffic74,227 by 2031
Trucks9%
Lanes on structure5
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
Detour if closed0.6 mi (1 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 statusHistorical significance not determinable at this time
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$19.8 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 93 NB over I 93 Sb/Austn St/Mbta built?

It was built in 2002, making it 23 years old in 2025.

What condition is I 93 NB over I 93 Sb/Austn St/Mbta 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 2022.

How much traffic does I 93 NB over I 93 Sb/Austn St/Mbta carry?

About 36,462 vehicles per day (2021 count), of which roughly 9% are trucks.

How long is I 93 NB over I 93 Sb/Austn St/Mbta?

The structure is 532 ft (162.3 m) long with a longest span of 148 ft (45.1 m) and a deck 72 ft wide.

Who owns I 93 NB over I 93 Sb/Austn St/Mbta?

It is owned by the State Highway Agency.