INTERSTATE 280
INTERSTATE 280 in 04-Sm-280-R25.04-Dlc, San Mateo County, California received a condition grade of C (55/100). Built in 1967, the bridge carries 178K vehicles daily on INTERSTATE 280 over Southgate Avenue. It is classified as structurally deficient.
Component Ratings
The riding surface — evaluated for cracking, spalling, and wear
Beams, girders, and trusses that support the deck
Piers, abutments, and foundations below the deck
Bridge Details
About This Bridge
INTERSTATE 280 is a 59-year-old bridge located 04-Sm-280-R25.04-Dlc in San Mateo County, California. The bridge carries INTERSTATE 280 over Southgate Avenue with 11 traffic lanes, handling approximately 178K vehicles per day. Built in 1967, the structure spans 56.4 meters.
The bridge received a Condition Grade of C (55/100) based on Federal Highway Administration inspection data. Its deck is rated 4/9 (poor), superstructure 5/9 (fair), and substructure 7/9 (good). 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
Frequently Asked Questions
INTERSTATE 280 has a Condition Score of 55/100 (Grade C). Its deck is rated 4/9, superstructure 5/9, and substructure 7/9 on the NBI scale. The bridge is classified as structurally deficient.
INTERSTATE 280 was built in 1967, making it 59 years old. The average bridge age in the United States is 48 years.
INTERSTATE 280 carries approximately 178K vehicles per day (average daily traffic). The bridge has 11 traffic lanes. It is 56.4 meters long and located on INTERSTATE 280 in 04-Sm-280-R25.04-Dlc, San Mateo County, California.
Yes, INTERSTATE 280 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.
INTERSTATE 280 is located 04-Sm-280-R25.04-Dlc in San Mateo County, California. The bridge carries INTERSTATE 280 over Southgate Avenue. Its coordinates are 37.674978, -122.469019. It is maintained by State Highway Agency.
INTERSTATE 280 carries INTERSTATE 280 over Southgate Avenue. The bridge is 56.4 meters long and was built in 1967.
Condition Score is calculated from deck (33%), superstructure (33%), and substructure (34%) NBI ratings with an age penalty for bridges over 50 years.