US Bridges

ST129 Billerica RD over US 3

Fair

Middlesex County, Massachusetts · Rt 129 at Rt 3 · Structure no. C08024AY7DOTNBI

Built
2004
21 years old
Condition
Fair
inspected May 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
285 ft
2 main spans
Daily traffic
25,000
2019 count
Owner
State
State Highway Agency

About this bridge

ST129 Billerica RD over US 3 is a steel continuous stringer/multi-beam or girder carrying ST129 Billerica RD over US 3 in Middlesex County, Massachusetts. It was built in 2004, so it is 21 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 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 25,000 vehicles a day, roughly 6% of them trucks, projected to reach 38,693 by 2032. The structure is 285 ft (87 m) long and 74 ft wide. If it were closed, the detour would be 7.5 mi (12 km).

Location

Open in Google Maps
CarriesST129 Billerica RD
CrossesUS 3
LocationRt 129 at Rt 3
RouteState Highway 129
CountyMiddlesex County
StateMassachusetts
Coordinates42.58898, -71.31297
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
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionMay 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry7: Better than present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating100.9 US tons
Inventory rating60.4 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 25 or greater
Structure length285 ft (87 m)
Longest span139 ft (42.5 m)
Deck width74 ft (22.7 m)
Roadway width66 ft (20.2 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic25,000 (2019)
Projected traffic38,693 by 2032
Trucks6%
Lanes on structure4
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
Detour if closed7.5 mi (12 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$3.9 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was ST129 Billerica RD over US 3 built?

It was built in 2004, making it 21 years old in 2025.

What condition is ST129 Billerica RD over US 3 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 May 2023.

How much traffic does ST129 Billerica RD over US 3 carry?

About 25,000 vehicles per day (2019 count), of which roughly 6% are trucks.

How long is ST129 Billerica RD over US 3?

The structure is 285 ft (87 m) long with a longest span of 139 ft (42.5 m) and a deck 74 ft wide.

Who owns ST129 Billerica RD over US 3?

It is owned by the State Highway Agency.