US Bridges

I 95 SB/ST128 SB over ST 3 A/Cambridge ST

Poor

Middlesex County, Massachusetts · At Junc. of I 95 & ST 3A · Structure no. B290102EVDOTNBI

Built
1950
75 years old, rebuilt 1964
Condition
Poor
inspected August 2023
Type
Stringer/Multi-beam or Girder
Steel
Length
205 ft
3 main spans
Daily traffic
93,600
2019 count
Owner
State
State Highway Agency

About this bridge

I 95 SB/ST128 SB over ST 3 A/Cambridge ST is a steel stringer/multi-beam or girder carrying I 95 SB/ST128 SB over ST 3 A/Cambridge ST in Middlesex County, Massachusetts. It was built in 1950 and reconstructed in 1964, 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: open, would be posted or closed except for temporary shoring.

It carries about 93,600 vehicles a day, roughly 10% of them trucks, projected to reach 252,530 by 2032. The structure is 205 ft (62.5 m) long and 74 ft wide.

CarriesI 95 SB/ST128 SB
CrossesST 3 A/Cambridge ST
LocationAt Junc. of I 95 & ST 3A
RouteInterstate 128
Coordinates42.48875, -71.19172
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure4 PoorAdvanced section loss, deterioration, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionAugust 2023
Inspection intervalevery 12 months
Operating statusOpen, would be posted or closed except for temporary shoring
ScourBridge not over waterway
Structural evaluation4: Meets minimum tolerable limits to be left in place as is
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.5 US tons
Inventory rating28.4 US tons

Structure

MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadH 20
Structure length205 ft (62.5 m)
Longest span105 ft (32 m)
Deck width74 ft (22.6 m)
Roadway width60 ft (18.3 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic93,600 (2019)
Projected traffic252,530 by 2032
Trucks10%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed—
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$25 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 95 SB/ST128 SB over ST 3 A/Cambridge ST built?

It was built in 1950, making it 75 years old in 2025. It was reconstructed in 1964.

What condition is I 95 SB/ST128 SB over ST 3 A/Cambridge ST in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in August 2023.

How much traffic does I 95 SB/ST128 SB over ST 3 A/Cambridge ST carry?

About 93,600 vehicles per day (2019 count), of which roughly 10% are trucks.

How long is I 95 SB/ST128 SB over ST 3 A/Cambridge ST?

The structure is 205 ft (62.5 m) long with a longest span of 105 ft (32 m) and a deck 74 ft wide.

Who owns I 95 SB/ST128 SB over ST 3 A/Cambridge ST?

It is owned by the State Highway Agency.