US Bridges

US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32

Fair

Suffolk County, Massachusetts · Bos Appr UP · Structure no. B160174WUDOTNBI

Built
1950
75 years old
Condition
Fair
inspected September 2023
Type
Girder and Floorbeam System
Steel
Length
2,072 ft
21 main spans
Daily traffic
40,790
2022 count
Owner
State
State Highway Agency

About this bridge

US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32 is a steel girder and floorbeam system carrying US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32 in Suffolk County, Massachusetts. It was built in 1950, so it is 75 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 40,790 vehicles a day, roughly 10% of them trucks, projected to reach 45,800 by 2032. The structure is 2,072 ft (631.6 m) long and 42 ft wide. If it were closed, the detour would be 5 mi (8 km).

Location

Open in Google Maps
CarriesUS 1 Sb/Bs U11-32
CrossesUS 1 Nb/Bos Lowr B11-32
LocationBos Appr UP
RouteU.S. Route 1
CountySuffolk County
StateMassachusetts
Coordinates42.37857, -71.05321
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
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 inspectionSeptember 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 geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment7: Better than present minimum criteria
Operating rating45 US tons
Inventory rating26.9 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckClosed grating
Main spans21 (+1 approach)
Design loadHS 20
Structure length2,072 ft (631.6 m)
Longest span110 ft (33.5 m)
Deck width42 ft (12.7 m)
Roadway width36 ft (11 m)
Vertical clearance over deck20 ft (6 m)

Traffic and service

Average daily traffic40,790 (2022)
Projected traffic45,800 by 2032
Trucks10%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed5 mi (8 km)
TollToll bridge
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$78.2 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32 built?

It was built in 1950, making it 75 years old in 2025.

What condition is US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32 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 September 2023.

How much traffic does US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32 carry?

About 40,790 vehicles per day (2022 count), of which roughly 10% are trucks.

How long is US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32?

The structure is 2,072 ft (631.6 m) long with a longest span of 110 ft (33.5 m) and a deck 42 ft wide.

Who owns US 1 Sb/Bs U11-32 over US 1 Nb/Bos Lowr B11-32?

It is owned by the State Highway Agency.