FHWA NBI 2024 Inspection record Public-domain dataset

MOUNT LASSEN DR SB

Carrying MOUNT LASSEN DR SB over MILLER CREEK

0.06 MI N LUCAS VALLEY RD, Marin, California

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
21 t Inventory load rating

Bridge Snapshot: MOUNT LASSEN DR SB

The MOUNT LASSEN DR SB bridge in Marin, California carries MOUNT LASSEN DR SB over MILLER CREEK. It was built in 1925, making it 101 years old today. The structure is built primarily of concrete and spans 1 section, stretching 9.2 meters (30 feet) end to end. Daily traffic averages 980 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 7/9, superstructure at 7/9, substructure at 6/9. The weakest component sits in fair condition. None of this bridge's reported major components fall into the Poor condition range. Its NBI inventory load rating is 21.1 metric tons.

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

How MOUNT LASSEN DR SB compares

▼ 10.2
Load rating vs California average (31.3 t)
Bottom 14%
Lower load rating than 86% of California bridges
217
Bridges in Marin · 18 in Poor condition
MOUNT LASSEN DR SB 21.1 t
California average 31.3 t

Live comparison across California.

Historical Sufficiency Rating

PlainBridge-computed
64.5 / 100 - historical 50–79.9 band
Structural adequacy /55
42.6
Serviceability /30
10.0
Essentiality /15
14.9
Special reductions
−3.0

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 How the historical reference is calculated.

Condition Ratings

Deck
7/9
Good (7–9)
Superstructure
7/9
Good (7–9)
Substructure
6/9
Fair (5–6)
Inventory Load Rating
21.1 t
NBI inventory level (metric tons)
Overall Condition
Fair

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

Structural Details

Year Built
1925
Material
Concrete
Number of Spans
1
Structure Length
9.2 m (30 ft)
Deck Width
7.2 m (24 ft)
Owner
County Highway Agency
Avg Daily Traffic
980 vehicles/day
Structure Number
27C0134

Condition Analysis

  • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
  • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
  • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.

How to read this record

This page shows what the last federal inspection recorded, not whether MOUNT LASSEN DR SB is safe to cross today. Here is how to use it.

  • NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
  • Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
  • Compare MOUNT LASSEN DR SB against other structures in Marin 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 MOUNT LASSEN DR SB?

MOUNT LASSEN DR SB in Marin, California has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.

How often is MOUNT LASSEN DR SB inspected?

MOUNT LASSEN DR SB'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 980 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. MOUNT LASSEN DR SB is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.

What is the inventory load rating for MOUNT LASSEN DR SB?

MOUNT LASSEN DR SB has an NBI inventory load rating of 21.1 metric tons.

Who is responsible for maintaining MOUNT LASSEN DR SB?

MOUNT LASSEN DR SB is owned and maintained by County Highway Agency.

How old is MOUNT LASSEN DR SB and does age affect safety?

MOUNT LASSEN DR SB was built in 1925, making it 101 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.