Grogans Mill Rd NB over Drainage Ditch
Montgomery County, Texas · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Grogans Mill Rd NB over Drainage Ditch in Montgomery County, Texas, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1978, making it 47 years old at the 2025 inventory.
- It carries about 20,000 vehicles a day (traffic count year 2013).
- Its listed owner is the county highway agency.
- It is one of 229 of the 711 inventoried bridges in Montgomery County rated fair (32.2%); 5 (0.7%) 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 October 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 → (30.12844, -95.45639)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Prestressed concrete multiple box beam |
| Length | about 78 ft |
| Location | 0.8 Mi W of Ih 45 |
| NBI structure number | 121700AA0681126 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2023 |
| 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 Texas department of transportation.
Busiest bridges in Montgomery County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Ih 45 over Drainage Ditch | 1926 | 243,893 | Fair |
| Ih 45 Sbml over Spring CR | 1990 | 243,893 | Fair |
| Ih 45 Nbml over Spring CR | 1990 | 243,893 | Fair |
| Ih 45 Sbml over Spring CR Rel | 1990 | 243,893 | Fair |
| Ih 45 Nbml over Spring CR Rel | 1990 | 243,893 | Fair |
| Ih 45 over Silverdale Crk | 2007 | 201,083 | Good |
All bridges nearby: Montgomery County, TX bridge conditions · every bridge in Montgomery County · Texas bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.