US Bridges

I 93 NB B5-B10 over Comb MBTA & I 93 SB

Fair

Suffolk County, Massachusetts · .8 MI N of Ramp I93&US1 · Structure no. B162813DYDOTNBI

Built
1970
55 years old
Condition
Fair
inspected April 2023
Type
Girder and Floorbeam System
Steel
Length
550 ft
5 main spans
Daily traffic
69,748
2022 count
Owner
State
State Highway Agency

About this bridge

I 93 NB B5-B10 over Comb MBTA & I 93 SB is a steel girder and floorbeam system carrying I 93 NB B5-B10 over Comb MBTA & I 93 SB 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 69,748 vehicles a day, roughly 9% of them trucks, projected to reach 94,600 by 2032. The structure is 550 ft (167.6 m) long and 62 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI 93 NB B5-B10
CrossesComb MBTA & I 93 SB
Location.8 MI N of Ramp 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.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionApril 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 geometry7: Better than present minimum criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating48.2 US tons
Inventory rating28.9 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans5
Design loadHS 20
Structure length550 ft (167.6 m)
Longest span139 ft (42.4 m)
Deck width62 ft (18.9 m)
Roadway width57 ft (17.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic69,748 (2022)
Projected traffic94,600 by 2032
Trucks9%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway and railroad
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$30.9 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 93 NB B5-B10 over Comb MBTA & I 93 SB built?

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

What condition is I 93 NB B5-B10 over Comb MBTA & I 93 SB 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 April 2023.

How much traffic does I 93 NB B5-B10 over Comb MBTA & I 93 SB carry?

About 69,748 vehicles per day (2022 count), of which roughly 9% are trucks.

How long is I 93 NB B5-B10 over Comb MBTA & I 93 SB?

The structure is 550 ft (167.6 m) long with a longest span of 139 ft (42.4 m) and a deck 62 ft wide.

Who owns I 93 NB B5-B10 over Comb MBTA & I 93 SB?

It is owned by the State Highway Agency.