US Bridges

ST146 SB over Water Blackstone River

Fair

Worcester County, Massachusetts · .1 Mi. N. of U.S.-20 · Structure no. M220597LWDOTNBI

Built
1997
28 years old
Condition
Fair
inspected November 2023
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
671 ft
4 main spans
Daily traffic
28,704
2023 count
Owner
State
State Highway Agency

About this bridge

ST146 SB over Water Blackstone River is a steel continuous stringer/multi-beam or girder carrying ST146 SB over Water Blackstone River in Worcester County, Massachusetts. It was built in 1997, so it is 28 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 28,704 vehicles a day, roughly 19% of them trucks, projected to reach 47,379 by 2032. The structure is 671 ft (204.4 m) long and 42 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesST146 SB
CrossesWater Blackstone River
Location.1 Mi. N. of U.S.-20
RouteState Highway 146
CountyWorcester County
StateMassachusetts
Coordinates42.21595, -71.78523
Functional classUrban Principal Arterial - Other Freeway or Expressway

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.
Channel and channel protection4 PoorAdvanced section loss, deterioration, spalling or scour.
Last inspectionNovember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Waterway adequacy9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating71.4 US tons
Inventory rating42.9 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length671 ft (204.4 m)
Longest span172 ft (52.5 m)
Deck width42 ft (12.9 m)
Roadway width39 ft (11.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic28,704 (2023)
Projected traffic47,379 by 2032
Trucks19%
Lanes on structure2
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
Detour if closed0.6 mi (1 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$4.3 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was ST146 SB over Water Blackstone River built?

It was built in 1997, making it 28 years old in 2025.

What condition is ST146 SB over Water Blackstone 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 November 2023.

How much traffic does ST146 SB over Water Blackstone River carry?

About 28,704 vehicles per day (2023 count), of which roughly 19% are trucks.

How long is ST146 SB over Water Blackstone River?

The structure is 671 ft (204.4 m) long with a longest span of 172 ft (52.5 m) and a deck 42 ft wide.

Who owns ST146 SB over Water Blackstone River?

It is owned by the State Highway Agency.