US Bridges

I 495 SB over ST110 Chelmsford ST

Fair

Middlesex County, Massachusetts · Rt 495 at Rt 110 · Structure no. C080252JADOTNBI

Built
1960
65 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
170 ft
3 main spans
Daily traffic
55,100
2025 count
Owner
State
State Highway Agency

About this bridge

I 495 SB over ST110 Chelmsford ST is a steel stringer/multi-beam or girder carrying I 495 SB over ST110 Chelmsford ST in Middlesex County, Massachusetts. It was built in 1960, so it is 65 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: open, would be posted or closed except for temporary shoring.

It carries about 55,100 vehicles a day, roughly 5% of them trucks, projected to reach 14,372 by 2031. The structure is 170 ft (51.9 m) long and 60 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI 495 SB
CrossesST110 Chelmsford ST
LocationRt 495 at Rt 110
RouteInterstate 495
CountyMiddlesex County
StateMassachusetts
Coordinates42.60546, -71.34442
Functional classUrban Principal Arterial - Interstate

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.
Superstructure7 GoodSome minor problems.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, would be posted or closed except for temporary shoring
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61.7 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length170 ft (51.9 m)
Longest span83 ft (25.3 m)
Deck width60 ft (18.3 m)
Roadway width52 ft (15.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic55,100 (2025)
Projected traffic14,372 by 2031
Trucks5%
Lanes on structure4
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedWidening with deck rehabilitation or replacement
Estimated improvement cost$15.1 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I 495 SB over ST110 Chelmsford ST built?

It was built in 1960, making it 65 years old in 2025.

What condition is I 495 SB over ST110 Chelmsford ST 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 December 2024.

How much traffic does I 495 SB over ST110 Chelmsford ST carry?

About 55,100 vehicles per day (2025 count), of which roughly 5% are trucks.

How long is I 495 SB over ST110 Chelmsford ST?

The structure is 170 ft (51.9 m) long with a longest span of 83 ft (25.3 m) and a deck 60 ft wide.

Who owns I 495 SB over ST110 Chelmsford ST?

It is owned by the State Highway Agency.