OLD STATE ROUTE 99
Carrying OLD STATE ROUTE 99 over MILES CREEK OVERFLOW
0.1 MI NW/O HEALY RD, Merced, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: OLD STATE ROUTE 99
The OLD STATE ROUTE 99 bridge in Merced, California carries OLD STATE ROUTE 99 over MILES CREEK OVERFLOW. It was built in 1938, making it 88 years old today. It was last reconstructed in 1987, extending its service life. The structure is built primarily of concrete continuous and spans 6 sections, stretching 27.1 meters (89 feet) end to end. Daily traffic averages 270 vehicles, placing it in the lower-traffic tier of California bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 4/9, substructure at 7/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 32.4 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How OLD STATE ROUTE 99 compares
Live comparison across California.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1938
- Last Reconstructed
- 1987
- Material
- Concrete Continuous
- Number of Spans
- 6
- Structure Length
- 27.1 m (89 ft)
- Deck Width
- 27.4 m (90 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 270 vehicles/day
- Structure Number
- 39C0392
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates poor at 4/9, advanced deterioration that should be prioritized for repair.
- • At 4/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear flagged for priority repair.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
How to read this record
OLD STATE ROUTE 99 is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare OLD STATE ROUTE 99 against other structures in Merced and across California. California bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for OLD STATE ROUTE 99?
OLD STATE ROUTE 99 in Merced, California has a deck rating of 4/9, superstructure rating of 4/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is OLD STATE ROUTE 99 inspected?
OLD STATE ROUTE 99's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 270 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. OLD STATE ROUTE 99 is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for OLD STATE ROUTE 99?
OLD STATE ROUTE 99 has an NBI inventory load rating of 32.4 metric tons.
Who is responsible for maintaining OLD STATE ROUTE 99?
OLD STATE ROUTE 99 is owned and maintained by County Highway Agency.
How old is OLD STATE ROUTE 99 and does age affect safety?
OLD STATE ROUTE 99 was built in 1938, making it 88 years old and last reconstructed in 1987.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.