I-78 WB over Nj Route 173
Hunterdon County, New Jersey · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- I-78 WB over Nj Route 173 in Hunterdon County, New Jersey, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1959, making it 66 years old at the 2025 inventory.
- It carries about 51,321 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 272 of the 373 inventoried bridges in Hunterdon County rated fair (72.9%); 26 (7.0%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated April 2023, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (40.66022, -75.07004)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 92 ft |
| Location | 0.43 Mi E of Rt 632 |
| NBI structure number | 1014151 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
Source: FHWA National Bridge Inventory, 2025 data as reported by the New Jersey department of transportation.
Busiest bridges in Hunterdon County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Rte I-78 & Ramp R over Beaver Brook | 1948 | 130,244 | Fair |
| I-78 over Beaver Brook | 1941 | 130,244 | Poor |
| I-78 over Branch Rockaway Creek | 1966 | 129,446 | Fair |
| I-78 EB over Beaver Brook | 1958 | 109,955 | Fair |
| I-78 over Tunnel Road | 1960 | 108,465 | Fair |
| I-78 EB over County Route 523 | 1965 | 107,826 | Fair |
All bridges nearby: Hunterdon County, NJ bridge conditions · every bridge in Hunterdon County · New Jersey bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.