In 2012 alone, cars spent a total of 6.6 million extra hours on the 5 due to heavy traffic. To add insult to injury, those 753 years only count the hours when the traffic was going less than 35 mph.
The California Department of Transportation data calculates the time wasted in "heavy congestion" using underground sensors that track vehicle speed. Caltrans did the math and then ranked freeways on a county level. The agency collects the data to identify which freeways most need traffic relief.
This is the second consecutive year the 5 has topped Caltrans' most-congested-freeways list. The reigning champion had been the stretch of the 405 Freeway that cuts across the western part of Los Angeles County.
Los Angeles County owned six of the top 10 slots, including the 5, 405, 101, 60, 10 and 210 freeways. The first outside L.A. County, coming in fifth, was I-5 in Orange County. Rounding out the list were the 405 in Orange County and the 580 and 80 freeways in Alameda County.
To ease the congestion, construction is underway for several stretches of the 5 in L.A. County to create carpool lanes. The county has grown by about four million people since the 5 opened more than 50 years ago. There are just too many cars for the capacity.
The statistics were released in February as part of Caltrans' first "Mile Marker" performance report. The Department of Transportation has been criticized as not being transparent about its operations, and the report was an effort to present useful information in a concise, accessible way, Caltrans spokesman Matt Rocco said.
The Associated Press contributed to this report.