US Bridges

ST 1 A/Main ST over RR Mbta/Csx

Fair

Norfolk County, Massachusetts · CSX Qbf MP Qbf 7.94 · Structure no. W0301740YDOT634

Built
1955
70 years old
Condition
Fair
inspected February 2024
Type
Girder and Floorbeam System
Steel
Length
91 ft
1 main span
Daily traffic
24,800
2024 count
Owner
State
State Highway Agency

About this bridge

ST 1 A/Main ST over RR Mbta/Csx is a steel girder and floorbeam system carrying ST 1 A/Main ST over RR Mbta/Csx in Norfolk County, Massachusetts. It was built in 1955, so it is 70 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 24,800 vehicles a day, roughly 3% of them trucks, projected to reach 16,109 by 2033. The structure is 91 ft (27.7 m) long and 59 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesST 1 A/Main ST
CrossesRR Mbta/Csx
LocationCSX Qbf MP Qbf 7.94
RouteState Highway 1A
CountyNorfolk County
StateMassachusetts
Coordinates42.13663, -71.25948
Functional classUrban Minor Arterial

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.
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 inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating41 US tons
Inventory rating20.8 US tons

Structure

Structure typeGirder and Floorbeam System
MaterialSteel
DeckConcrete, cast-in-place
Main spans1
Design loadH 20
Structure length91 ft (27.7 m)
Longest span89 ft (27.1 m)
Deck width59 ft (18 m)
Roadway width46 ft (14 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24,800 (2024)
Projected traffic16,109 by 2033
Trucks3%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesRailroad
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

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$4.9 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was ST 1 A/Main ST over RR Mbta/Csx built?

It was built in 1955, making it 70 years old in 2025.

What condition is ST 1 A/Main ST over RR Mbta/Csx 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 February 2024.

How much traffic does ST 1 A/Main ST over RR Mbta/Csx carry?

About 24,800 vehicles per day (2024 count), of which roughly 3% are trucks.

How long is ST 1 A/Main ST over RR Mbta/Csx?

The structure is 91 ft (27.7 m) long with a longest span of 89 ft (27.1 m) and a deck 59 ft wide.

Who owns ST 1 A/Main ST over RR Mbta/Csx?

It is owned by the State Highway Agency.