US Bridges

ST 18 Bedford ST over I 495

Fair

Plymouth County, Massachusetts · 1 M S of RTE 44 / 495 · Structure no. M1805247DDOTNBI

Built
1958
67 years old, rebuilt 1987
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel
Length
317 ft
4 main spans
Daily traffic
14,214
2024 count
Owner
State
State Highway Agency

About this bridge

ST 18 Bedford ST over I 495 is a steel stringer/multi-beam or girder carrying ST 18 Bedford ST over I 495 in Plymouth County, Massachusetts. It was built in 1958 and reconstructed in 1987, so it is 67 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.

It carries about 14,214 vehicles a day, roughly 4% of them trucks, projected to reach 23,967 by 2032. The structure is 317 ft (96.6 m) long and 53 ft wide. If it were closed, the detour would be 3.1 mi (5 km).

Location

Open in Google Maps
CarriesST 18 Bedford ST
CrossesI 495
Location1 M S of RTE 44 / 495
RouteState Highway 18
CountyPlymouth County
StateMassachusetts
Coordinates41.89851, -70.95851
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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no 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 alignment8: Equal to present desirable criteria
Operating rating48.2 US tons
Inventory rating28.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel
DeckConcrete, cast-in-place
Main spans4
Design loadH 20
Structure length317 ft (96.6 m)
Longest span109 ft (33.2 m)
Deck width53 ft (16.2 m)
Roadway width45 ft (13.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic14,214 (2024)
Projected traffic23,967 by 2032
Trucks4%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway
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 statusPossibly eligible for the National Register; requires further investigation
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$15.3 million (2025 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was ST 18 Bedford ST over I 495 built?

It was built in 1958, making it 67 years old in 2025. It was reconstructed in 1987.

What condition is ST 18 Bedford ST over I 495 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 November 2024.

How much traffic does ST 18 Bedford ST over I 495 carry?

About 14,214 vehicles per day (2024 count), of which roughly 4% are trucks.

How long is ST 18 Bedford ST over I 495?

The structure is 317 ft (96.6 m) long with a longest span of 109 ft (33.2 m) and a deck 53 ft wide.

Who owns ST 18 Bedford ST over I 495?

It is owned by the State Highway Agency.