ST 99 Alford ST over Water Mystic River
FairSuffolk County, Massachusetts · At Mystic River · Structure no. B16029388MUNNBI
- Built
- 1963
- 62 years old, rebuilt 2014
- Condition
- Fair
- inspected June 2024
- Type
- Movable - Bascule
- Steel
- Length
- 825 ft
- 1 main span
- Daily traffic
- 40,000
- 2022 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
ST 99 Alford ST over Water Mystic River is a steel movable - bascule carrying ST 99 Alford ST over Water Mystic River in Suffolk County, Massachusetts. It was built in 1963 and reconstructed in 2014, so it is 62 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 40,000 vehicles a day, roughly 6% of them trucks, projected to reach 86,862 by 2031. The structure is 825 ft (251.5 m) long and 95 ft wide. If it were closed, the detour would be 3.7 mi (6 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was ST 99 Alford ST over Water Mystic River built?
It was built in 1963, making it 62 years old in 2025. It was reconstructed in 2014.
What condition is ST 99 Alford ST over Water Mystic 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 June 2024.
How much traffic does ST 99 Alford ST over Water Mystic River carry?
About 40,000 vehicles per day (2022 count), of which roughly 6% are trucks.
How long is ST 99 Alford ST over Water Mystic River?
The structure is 825 ft (251.5 m) long with a longest span of 159 ft (48.6 m) and a deck 95 ft wide.
Who owns ST 99 Alford ST over Water Mystic River?
It is owned by the City or Municipal Highway Agency.