Santa Ana Freeway

Interstate 5; the Santa Ana Freeway segment is highlighted in purple, the Golden State Freeway segment is highlighted in red, and the San Diego Freeway segment is highlighted in blue.

The Santa Ana Freeway is one of the principal freeways in Southern California, connecting Los Angeles, California and its southeastern suburbs. The freeway begins at the four level Bill Keene Memorial Interchange complex in downtown Los Angeles, signed as U.S. Route 101. From there, it proceeds one mile east to the East Los Angeles Interchange where it takes the designation of Interstate 5. Its alignment then generally goes northwest to southeast towards its junction with the San Diego Freeway, Interstate 405 (I-405) (informally referred to as the El Toro Y), in Irvine.

North of the East Los Angeles Interchange complex, Interstate 5's name changes to the Golden State Freeway. South of its junction with the I-405, its name changes to the San Diego Freeway. (Interstate 405 ends at this junction.)

An abundance of landmarks, most importantly (Disneyland and Angel Stadium of Anaheim) in Anaheim, along the Orange County portion of its route combines with a severe bottleneck beginning at the Los Angeles County border (shrinking from 12 to 6 lanes) to make it one of the most congested freeways in Southern California. The infamously busy intersection of the Santa Ana, Garden Grove, and Orange freeways in southwestern Orange is nicknamed the Orange Crush. The section between Orange and Los Angeles County Line to East Los Angeles is highly congested with traffic.

The entire Santa Ana Freeway was originally signed as US-101(prior to 1964) before the segment of the 101 between the East Los Angeles Interchange and the United States–Mexico border in San Ysidro, California was decommissioned in favor of Interstate 5.