Williamsville Road over Portage River
Livingston County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Williamsville Road over Portage River in Livingston County, Michigan, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, 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 672 vehicles a day (traffic count year 2013).
- Its listed owner is the county highway agency.
- It is one of 95 of the 165 inventoried bridges in Livingston County rated fair (57.6%); 23 (13.9%) 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 June 2024, 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 → (42.43645, -84.09388)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 44 ft |
| Location | Sec 33 Unadilla Twp |
| NBI structure number | 000000000005805 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | June 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Michigan department of transportation.
Busiest bridges in Livingston County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US-23 over M-36 | 1960 | 64,800 | Poor |
| I-96 WB Cd over US-23 SB | 2016 | 51,600 | Good |
| I-96 WB over US-23 SB | 2015 | 51,600 | Fair |
| I-96 EB over US-23 NB | 2015 | 51,600 | Fair |
| I-96 WB over US-23 NB | 2015 | 51,600 | Fair |
| I-96 EB Cd over US-23 SB | 2016 | 51,588 | Good |
All bridges nearby: Livingston County, MI bridge conditions · every bridge in Livingston County · Michigan bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.