The El Toro "Y" is a freeway interchange in southern Orange County, California where the Santa Ana Freeway, Interstate 5 (I-5), and the San Diego Freeway, the I-405 merge. South of that point, it retains the name "San Diego Freeway" but with the highway designation "I-5." Located in south Orange County where the cities of Lake Forest, Laguna Hills, and Irvine converge, the interchange was named after the city (El Toro - now Lake Forest) and the now closed Marine Corps Air Station El Toro, located northeast of the interchange.The "Y" is one of the busiest interchanges in the world; from 1975 to 2002, daily traffic surged from 102,000 to 356,000 vehicles a day.HistoryBy the early 1990s the El Toro Y had become one of the most congested freeway interchanges in the world, its severe overcrowding fed by a housing boom in southern Orange County.In November 1990, Orange County voters approved Measure M, a half-cent increase in the county sales tax to finance transportation improvements. In 1993, the California Department of Transportation (Caltrans) began a massive expansion project, adding a new interchange and collector/distributor roads at Bake Parkway (signed as truck bypass lanes) and Lake Forest Drive, and carpool lanes and connectors. The $166-million project also vastly increased regular traffic lanes. After the project was completed in 1997, the El Toro Y stood as one of the widest roads in the world, at 26 traffic lanes wide.
