Structure L040042PXMUNNBI · Essex County, MA
Carries HWY Union ST over Water North Canal, .32 Km North Merrimac R.
76 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 multi-beam bridge.
| State | Massachusetts |
| County | Essex |
| Location | .32 Km North Merrimac R |
| Carries | HWY Union ST |
| Crosses | Water North Canal |
| Coordinates | 42.70632, -71.15341 |
| Material | Steel |
| Design | Stringer/Multi-beam |
| Total Length | 76.1 ft (23.2 m) |
| Max Span | 72.2 ft (22 m) |
| Deck Width | 49.9 ft (15.2 m) |
| Deck Area | 352.6 sq m |
| Main Spans | 1 |
| Year Built | 1860 (reconstructed 1939) |
| Avg Daily Traffic | 18,300 (2024) |
| Truck Traffic | 3% |
| Lanes On Bridge | 3 |
| Last Inspection | April 2024 |
| Inspection Frequency | Every 6 months |
| Owner | City/Municipal Highway Agency |
| Historical Significance | Historical significance is not determined |
| Scour Critical | 7 — Countermeasures installed |
| Structure Number | L040042PXMUNNBI |
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.