US Bridges

US 20 Main ST over RR Mbta/Bmrr

FairPosted for load

Middlesex County, Massachusetts · .16 KM E JCT 60 & 20 · Structure no. W040152NHDOT634

Built
1936
89 years old, rebuilt 1991
Condition
Fair
inspected February 2024
Type
Truss - Thru
Steel
Length
234 ft
1 main span
Daily traffic
28,190
2020 count
Owner
State
State Highway Agency

About this bridge

US 20 Main ST over RR Mbta/Bmrr is a steel truss - thru carrying US 20 Main ST over RR Mbta/Bmrr in Middlesex County, Massachusetts. It was built in 1936 and reconstructed in 1991, so it is 89 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. Its operating status is: posted for load restriction.

It carries about 28,190 vehicles a day, roughly 3% of them trucks, projected to reach 43,589 by 2033. The structure is 234 ft (71.3 m) long and 85 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesUS 20 Main ST
CrossesRR Mbta/Bmrr
Location.16 KM E JCT 60 & 20
RouteU.S. Route 20
CountyMiddlesex County
StateMassachusetts
Coordinates42.37786, -71.22364
Functional classUrban Other Principal 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.
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 inspectionFebruary 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourBridge not over waterway
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment7: Better than present minimum criteria
Operating rating69.4 US tons
Inventory rating41.6 US tons

Structure

Structure typeTruss - Thru
MaterialSteel
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadH 20
Structure length234 ft (71.3 m)
Longest span115 ft (35.1 m)
Deck width85 ft (25.9 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic28,190 (2020)
Projected traffic43,589 by 2033
Trucks3%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesRailroad
Detour if closed3.1 mi (5 km)
TollOn a free road
National Highway SystemYes

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$18.2 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was US 20 Main ST over RR Mbta/Bmrr built?

It was built in 1936, making it 89 years old in 2025. It was reconstructed in 1991.

What condition is US 20 Main ST 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 February 2024.

How much traffic does US 20 Main ST over RR Mbta/Bmrr carry?

About 28,190 vehicles per day (2020 count), of which roughly 3% are trucks.

How long is US 20 Main ST over RR Mbta/Bmrr?

The structure is 234 ft (71.3 m) long with a longest span of 115 ft (35.1 m) and a deck 85 ft wide.

Who owns US 20 Main ST over RR Mbta/Bmrr?

It is owned by the State Highway Agency.