What is the most congested stretch of California freeway? The title goes to Interstate 5 in Los Angeles County. San Diego’s “best” ranking is merely number 16 for traffic congestion.
Caltrans measures freeway traffic congestion throughout the state to determine which freeways have the greatest need for improvement. Half of the most congested freeways in the state, listed here, are in Los Angeles County, with Interstate 5 being No. 1.
Route County Vehicle Hours of Delay*
5 Los Angeles 6,581,609
405 Los Angeles 5,722,148
101 Los Angeles 4,516,141
60 Los Angeles 4,440,585
5 Orange 3,346,209
10 Los Angeles 3,294,890
210 Los Angeles 3,152,598
405 Orange 3,119,284
580 Alameda 2,648,174
80 Alameda 2,520,715
110 Los Angeles 2,402,760
101 Santa Clara 2,392,486
880 Alameda 2,015,921
91 Riverside 1,888,264
605 Los Angeles 1,878,749
5 San Diego 1,820,953
* (at 35 mph) 2012
