State Route 99 over Athlone Drain
Merced County, California · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- State Route 99 over Athlone Drain in Merced County, California, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 2015, making it 10 years old at the 2025 inventory.
- It carries about 39,000 vehicles a day (traffic count year 2009).
- Its listed owner is the state highway agency.
- It is one of 195 of the 532 inventoried bridges in Merced County rated good (36.7%); 23 (4.3%) 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 2024, on a 48-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (37.22146, -120.37085)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 7 | 7 | Good condition |
Bridge details
| Structure | Continuous concrete culvert |
| Length | about 21 ft |
| Location | 10-mer-099-6.49 |
| NBI structure number | 39 0247 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2024 |
| Inspection interval (item 91) | 48 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Merced County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| State Route 99 over Turlock Canal | 1935 | 65,000 | Fair |
| State Route 99 NB over 15TH Street | 1962 | 51,000 | Fair |
| State Route 99 over West 16TH St UP RR | 2013 | 51,000 | Fair |
| State Route 99 over UPRR & 16TH Street | 2015 | 51,000 | Fair |
| State Route 99 SB over El Capitan Way | 1980 | 37,000 | Fair |
| State Route 99 NB over El Capitan Way | 1980 | 37,000 | Fair |
All bridges nearby: Merced County, CA bridge conditions · every bridge in Merced County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.