US Bridges

I 93 SB B5-B10 over RR Mbta/Bmrr

Fair

Suffolk County, Massachusetts · .9 MI N of JCT I93&US1 · Structure no. B162813EDDOTNBI

Built
1970
55 years old
Condition
Fair
inspected July 2023
Type
Girder and Floorbeam System
Steel
Length
550 ft
5 main spans
Daily traffic
57,435
2022 count
Owner
State
State Highway Agency

About this bridge

I 93 SB B5-B10 over RR Mbta/Bmrr is a steel girder and floorbeam system carrying I 93 SB B5-B10 over RR Mbta/Bmrr in Suffolk County, Massachusetts. It was built in 1970, so it is 55 years old, younger 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 57,435 vehicles a day, roughly 9% of them trucks, projected to reach 108,498 by 2032. The structure is 550 ft (167.6 m) long and 57 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 93 SB B5-B10
CrossesRR Mbta/Bmrr
Location.9 MI N of JCT I93&US1
RouteInterstate 93
CountySuffolk County
StateMassachusetts
Coordinates42.38125, -71.07666
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 inspectionJuly 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 geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating52.8 US tons
Inventory rating31.6 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20 + Mod
Structure length550 ft (167.6 m)
Longest span139 ft (42.4 m)
Deck width57 ft (17.4 m)
Roadway width45 ft (13.7 m)
Vertical clearance over deck17 ft (5.1 m)

Traffic and service

Average daily traffic57,435 (2022)
Projected traffic108,498 by 2032
Trucks9%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesRailroad
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$28.5 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 93 SB B5-B10 over RR Mbta/Bmrr built?

It was built in 1970, making it 55 years old in 2025.

What condition is I 93 SB B5-B10 over RR Mbta/Bmrr 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 July 2023.

How much traffic does I 93 SB B5-B10 over RR Mbta/Bmrr carry?

About 57,435 vehicles per day (2022 count), of which roughly 9% are trucks.

How long is I 93 SB B5-B10 over RR Mbta/Bmrr?

The structure is 550 ft (167.6 m) long with a longest span of 139 ft (42.4 m) and a deck 57 ft wide.

Who owns I 93 SB B5-B10 over RR Mbta/Bmrr?

It is owned by the State Highway Agency.