BridgeSafety
Marin County, CA · Structure #27 0006

U.S. HIGHWAY 101

U.S. HIGHWAY 101 in 04-Mrn-101-13.99-Srf, Marin County, California received a condition grade of F (0/100). Built in 1951, the bridge carries 159K vehicles daily on U.S. HIGHWAY 101 over N Branch Gallinas Creek. It is classified as structurally deficient.

F
0/100
0
Condition Score
159K
Daily Traffic
1951
Year Built
13.1m
Length

Component Ratings

DeckSerious
0/9

The riding surface — evaluated for cracking, spalling, and wear

SuperstructureSerious
0/9

Beams, girders, and trusses that support the deck

SubstructureSerious
0/9

Piers, abutments, and foundations below the deck

Bridge Details

Road
U.S. HIGHWAY 101
Crosses Over
N Branch Gallinas Creek
State
California
County
Marin County
Location
04-Mrn-101-13.99-Srf
Year Built
1951
Reconstructed
1961
Age
75 years
Daily Traffic
159,000
Lanes
10
Length
13.1 meters
Owner
State Highway Agency
Structure Number
27 0006

About This Bridge

U.S. HIGHWAY 101 is a 75-year-old bridge located 04-Mrn-101-13.99-Srf in Marin County, California. The bridge carries U.S. HIGHWAY 101 over N Branch Gallinas Creek with 10 traffic lanes, handling approximately 159K vehicles per day. Built in 1951 and reconstructed in 1961, the structure spans 13.1 meters.

The bridge received a Condition Grade of F (0/100) based on Federal Highway Administration inspection data. Its deck is rated 0/9 (serious), superstructure 0/9 (serious), and substructure 0/9 (serious). The bridge is classified as structurally deficient, meaning at least one major component is rated 4 or below — this signals a need for repair or replacement but does not necessarily indicate an immediate safety hazard.

This bridge is owned and maintained by State Highway Agency.

Location Map

04-Mrn-101-13.99-Srf, Marin County, California

38.011153, -122.541769

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Frequently Asked Questions

U.S. HIGHWAY 101 has a Condition Score of 0/100 (Grade F). Its deck is rated 0/9, superstructure 0/9, and substructure 0/9 on the NBI scale. The bridge is classified as structurally deficient.

U.S. HIGHWAY 101 was built in 1951 and reconstructed in 1961, making it 75 years old. The average bridge age in the United States is 48 years.

U.S. HIGHWAY 101 carries approximately 159K vehicles per day (average daily traffic). The bridge has 10 traffic lanes. It is 13.1 meters long and located on U.S. HIGHWAY 101 in 04-Mrn-101-13.99-Srf, Marin County, California.

Yes, U.S. HIGHWAY 101 is classified as structurally deficient because at least one of its primary components (deck, superstructure, or substructure) is rated 4 or below on the 0-9 NBI scale. This does not necessarily mean it is unsafe, but it requires significant repair or replacement.

U.S. HIGHWAY 101 is located 04-Mrn-101-13.99-Srf in Marin County, California. The bridge carries U.S. HIGHWAY 101 over N Branch Gallinas Creek. Its coordinates are 38.011153, -122.541769. It is maintained by State Highway Agency.

U.S. HIGHWAY 101 carries U.S. HIGHWAY 101 over N Branch Gallinas Creek. The bridge is 13.1 meters long and was built in 1951, with reconstruction in 1961.

Last updated:

Condition Score is calculated from deck (33%), superstructure (33%), and substructure (34%) NBI ratings with an age penalty for bridges over 50 years.