US Bridges

ST 3 A/Boston RD over Water Concord River

Fair

Middlesex County, Massachusetts · 1 MI N of Billerica Ctr · Structure no. B120032DGDOTNBI

Built
1920
105 years old
Condition
Fair
inspected October 2024
Type
Arch - Deck
Concrete
Length
180 ft
3 main spans
Daily traffic
18,283
2023 count
Owner
State
State Highway Agency

About this bridge

ST 3 A/Boston RD over Water Concord River is a concrete arch - deck carrying ST 3 A/Boston RD over Water Concord River in Middlesex County, Massachusetts. It was built in 1920, so it is 105 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 6 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 18,283 vehicles a day, roughly 7% of them trucks, projected to reach 34,745 by 2031. The structure is 180 ft (54.9 m) long and 40 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesST 3 A/Boston RD
CrossesWater Concord River
Location1 MI N of Billerica Ctr
RouteState Highway 3A
CountyMiddlesex County
StateMassachusetts
Coordinates42.5741, -71.28022
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
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
Structural evaluation6: Equal to present minimum criteria
Deck geometry3: Basically intolerable, requiring high priority of corrective action
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment6: Equal to present minimum criteria
Operating rating102.7 US tons
Inventory rating62.6 US tons

Structure

Structure typeArch - Deck
MaterialConcrete
DeckNot applicable
Main spans3
Design loadH 20
Structure length180 ft (54.9 m)
Longest span65 ft (19.8 m)
Deck width40 ft (12.1 m)
Roadway width30 ft (9.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,283 (2023)
Projected traffic34,745 by 2031
Trucks7%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
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 proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$5.4 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was ST 3 A/Boston RD over Water Concord River built?

It was built in 1920, making it 105 years old in 2025.

What condition is ST 3 A/Boston RD over Water Concord River 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 October 2024.

How much traffic does ST 3 A/Boston RD over Water Concord River carry?

About 18,283 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is ST 3 A/Boston RD over Water Concord River?

The structure is 180 ft (54.9 m) long with a longest span of 65 ft (19.8 m) and a deck 40 ft wide.

Who owns ST 3 A/Boston RD over Water Concord River?

It is owned by the State Highway Agency.