US 101 MCDONNELL
US 101 MCDONNELL in 04-Sm-101-18.09-Mlbr, San Mateo County, California received a condition grade of F (0/100). Built in 1947, the bridge carries 226K vehicles daily on US 101 MCDONNELL over Millbrae Slough. 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
US 101 MCDONNELL is a 79-year-old bridge located 04-Sm-101-18.09-Mlbr in San Mateo County, California. The bridge carries US 101 MCDONNELL over Millbrae Slough with 17 traffic lanes, handling approximately 226K vehicles per day. Built in 1947 and reconstructed in 1961, the structure spans 10.4 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
Frequently Asked Questions
US 101 MCDONNELL 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.
US 101 MCDONNELL was built in 1947 and reconstructed in 1961, making it 79 years old. The average bridge age in the United States is 48 years.
US 101 MCDONNELL carries approximately 226K vehicles per day (average daily traffic). The bridge has 17 traffic lanes. It is 10.4 meters long and located on US 101 MCDONNELL in 04-Sm-101-18.09-Mlbr, San Mateo County, California.
Yes, US 101 MCDONNELL 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.
US 101 MCDONNELL is located 04-Sm-101-18.09-Mlbr in San Mateo County, California. The bridge carries US 101 MCDONNELL over Millbrae Slough. Its coordinates are 37.604061, -122.382264. It is maintained by State Highway Agency.
US 101 MCDONNELL carries US 101 MCDONNELL over Millbrae Slough. The bridge is 10.4 meters long and was built in 1947, with reconstruction in 1961.
Condition Score is calculated from deck (33%), superstructure (33%), and substructure (34%) NBI ratings with an age penalty for bridges over 50 years.