Glenbrook Road over Portage River
Livingston County, Michigan · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Glenbrook 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 culvert, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1960, making it 65 years old at the 2025 inventory.
- It carries about 640 vehicles a day (traffic count year 2014).
- 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.
- 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 → (42.42482, -84.00374)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Culvert | 5 | Fair condition |
Bridge details
| Structure | Steel culvert |
| Length | about 23 ft |
| Location | Sec 31-32 Putnam Twp |
| NBI structure number | 000000000005833 |
| Condition class | Fair |
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 |
|---|---|---|---|
| I-96 EB Cd over US-23 NB | 2016 | 516,020 | Good |
| 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 |
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.