US Bridges

HWY Prospect ST over Water Charles River

Fair

Middlesex County, Massachusetts · .6 Mi. S. Main St. · Structure no. W040052CBMUNNBI

Built
1888
137 years old, rebuilt 1975
Condition
Fair
inspected May 2024
Type
Arch - Deck
Masonry
Length
132 ft
3 main spans
Daily traffic
31,500
2021 count
Owner
City
City or Municipal Highway Agency

About this bridge

HWY Prospect ST over Water Charles River is a masonry arch - deck carrying HWY Prospect ST over Water Charles River in Middlesex County, Massachusetts. It was built in 1888 and reconstructed in 1975, so it is 137 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 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 31,500 vehicles a day, roughly 2% of them trucks, projected to reach 42,957 by 2032. The structure is 132 ft (40.2 m) long and 45 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesHWY Prospect ST
CrossesWater Charles River
Location.6 Mi. S. Main St.
RouteCity Street 0
CountyMiddlesex County
StateMassachusetts
Coordinates42.36881, -71.24355
Functional classUrban Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourScour critical; foundations unstable for calculated scour conditions
Structural evaluation6: Equal to present minimum criteria
Deck geometry2: Basically intolerable, requiring high priority of replacement
Waterway adequacy7: Better than present minimum criteria
Approach roadway alignment5: Somewhat better than minimum adequacy to tolerate being left in place as is
Operating rating70.1 US tons
Inventory rating70 US tons

Structure

Structure typeArch - Deck
MaterialMasonry
DeckNot applicable
Main spans3
Design loadHS 20
Structure length132 ft (40.2 m)
Longest span46 ft (14 m)
Deck width45 ft (13.8 m)
Roadway width32 ft (9.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic31,500 (2021)
Projected traffic42,957 by 2032
Trucks2%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedWidening of existing bridge without deck rehabilitation
Estimated improvement cost$6.4 million (2025 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was HWY Prospect ST over Water Charles River built?

It was built in 1888, making it 137 years old in 2025. It was reconstructed in 1975.

What condition is HWY Prospect ST over Water Charles 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 May 2024.

How much traffic does HWY Prospect ST over Water Charles River carry?

About 31,500 vehicles per day (2021 count), of which roughly 2% are trucks.

How long is HWY Prospect ST over Water Charles River?

The structure is 132 ft (40.2 m) long with a longest span of 46 ft (14 m) and a deck 45 ft wide.

Who owns HWY Prospect ST over Water Charles River?

It is owned by the City or Municipal Highway Agency.