St 9 Boylston St over Tr Green Line D
Middlesex County, Massachusetts · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- St 9 Boylston St over Tr Green Line D in Middlesex County, Massachusetts, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1905 and reconstructed in 1960, making it 120 years old at the 2025 inventory.
- It carries about 96,206 vehicles a day (traffic count year 2017).
- Its listed owner is the state highway agency.
- It is one of 91 of the 821 inventoried bridges in Middlesex County rated poor (11.1%); 91 (11.1%) are rated poor.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (42.31938, -71.20859)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 5 | Fair condition |
| Superstructure | 4 | Poor condition |
| Substructure | 5 | Fair condition |
Bridge details
| Structure | Steel girder and floorbeam |
| Length | about 56 ft |
| Location | 2.3 Km Ely Rt 128 |
| NBI structure number | N120402EEDOTNBI |
| Condition class | Poor |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Massachusetts department of transportation.
Busiest bridges in Middlesex County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 93 over St 60 Eb/salem St | 1961 | 266,500 | Fair |
| I 93 over St 60 Wb/salem St | 1961 | 266,500 | Fair |
| I 93 over Water Mystic River | 1963 | 250,350 | Fair |
| I 93 over Hwy Valley St & Fllswy | 1961 | 210,316 | Fair |
| I 93 over Hwy Montvale Ave | 1958 | 208,231 | Fair |
| I 93 over I 95 /ST128 | 1957 | 200,824 | Poor |
All bridges nearby: Middlesex County, MA bridge conditions · every bridge in Middlesex County · Massachusetts bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.