Structure N120402EEDOTNBI · Middlesex County, MA
Carries ST 9 Boylston ST over Tr Green Line D, 2.3 Km Ely RT 128.
56 ft end to end. Lengths and the car on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a girder bridge.
| State | Massachusetts |
| County | Middlesex |
| Location | 2.3 Km Ely RT 128 |
| Carries | ST 9 Boylston ST |
| Crosses | Tr Green Line D |
| Coordinates | 42.31938, -71.20859 |
| Material | Steel |
| Design | Girder and Floorbeam |
| Total Length | 56.1 ft (17.1 m) |
| Max Span | 49.9 ft (15.2 m) |
| Deck Width | 89.9 ft (27.4 m) |
| Deck Area | 468.5 sq m |
| Main Spans | 1 |
| Year Built | 1905 (reconstructed 1960) |
| Avg Daily Traffic | 96,206 (2017) |
| Truck Traffic | 4% |
| Lanes On Bridge | 4 |
| Last Inspection | December 2022 |
| Inspection Frequency | Every 12 months |
| Owner | State Highway Agency |
| Historical Significance | Historical significance is not determined |
| Scour Critical | Not applicable |
| Structure Number | N120402EEDOTNBI |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.