S101 ON & OFF RAMP
Carrying S101 ON & OFF RAMP over U.S. HIGHWAY 101
04-MRN-101-25.50, Marin, California
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: S101 ON & OFF RAMP
The S101 ON & OFF RAMP bridge in Marin, California carries S101 ON & OFF RAMP over U.S. HIGHWAY 101. It was built in 2006, making it 20 years old today. The structure is built primarily of prestressed concrete continuous. Daily traffic averages 80,000 vehicles, placing it in the heavily-trafficked tier of California bridges.
The latest FHWA inspection records show limited component ratings on file. The weakest component sits in unrated condition. None of this bridge's reported major components fall into the Poor condition range.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How S101 ON & OFF RAMP 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 How the historical reference is calculated.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
- 2006
- Material
- Prestressed Concrete Continuous
- Avg Daily Traffic
- 80,000 vehicles/day
- Structure Number
- 27 0115
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether S101 ON & OFF RAMP 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 S101 ON & OFF RAMP 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 S101 ON & OFF RAMP?
S101 ON & OFF RAMP in Marin, California on the FHWA's 0–9 scale.
How often is S101 ON & OFF RAMP inspected?
S101 ON & OFF RAMP'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 80,000 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. S101 ON & OFF RAMP is currently shown as unrated condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for S101 ON & OFF RAMP?
An inventory load rating is not recorded for S101 ON & OFF RAMP.
Who is responsible for maintaining S101 ON & OFF RAMP?
Ownership is not specified for S101 ON & OFF RAMP in the NBI.
How old is S101 ON & OFF RAMP and does age affect safety?
S101 ON & OFF RAMP was built in 2006, making it 20 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.
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.