FHWA NBI 2024 Inspection record Public-domain dataset

MATTOLE ROAD

Carrying MATTOLE ROAD over MATTOLE RIVER

8.0 MI N/O HONEYDEW, Humboldt, California

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Poor
18 t Inventory load rating

Bridge Snapshot: MATTOLE ROAD

The MATTOLE ROAD bridge in Humboldt, California carries MATTOLE ROAD over MATTOLE RIVER. It was built in 1935, making it 91 years old today. The structure is built primarily of concrete and spans 1 section, stretching 50.6 meters (166 feet) end to end. Daily traffic averages 205 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 superstructure at 5/9, substructure at 4/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order. Its NBI inventory load rating is 18.1 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How MATTOLE ROAD compares

▼ 13.2
Load rating vs California average (31.3 t)
Bottom 10%
Lower load rating than 90% of California bridges
398
Bridges in Humboldt · 25 in Poor condition
MATTOLE ROAD 18.1 t
California average 31.3 t

Live comparison across California.

Historical Sufficiency Rating

PlainBridge-computed
30.1 / 100 - historical 20–49.9 band
Structural adequacy /55
12.4
Serviceability /30
10.0
Essentiality /15
7.7
Special reductions
0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Superstructure
5/9
Fair (5–6)
Substructure
4/9
Poor (1–4)
Inventory Load Rating
18.1 t
NBI inventory level (metric tons)
Overall Condition
Poor

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1935
Material
Concrete
Number of Spans
1
Structure Length
50.6 m (166 ft)
Deck Width
5.5 m (18 ft)
Owner
County Highway Agency
Avg Daily Traffic
205 vehicles/day
Structure Number
04C0189

Condition Analysis

  • The superstructure (beams and supports above the deck) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
  • At 4/9, the substructure (piers and abutments) is in poor shape, with advanced wear flagged for priority repair.

How to read this record

MATTOLE ROAD 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 MATTOLE ROAD against other structures in Humboldt 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 MATTOLE ROAD?

MATTOLE ROAD in Humboldt, California, superstructure rating of 5/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.

How often is MATTOLE ROAD inspected?

MATTOLE ROAD'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 205 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. MATTOLE ROAD 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 MATTOLE ROAD?

MATTOLE ROAD has an NBI inventory load rating of 18.1 metric tons.

Who is responsible for maintaining MATTOLE ROAD?

MATTOLE ROAD is owned and maintained by County Highway Agency.

How old is MATTOLE ROAD and does age affect safety?

MATTOLE ROAD was built in 1935, making it 91 years old.

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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.