[Tourmaline]

Originally Posted by GaylordWilshire

Which reminds me of the frequently asked question, "Why are LA freeways now referred to as 'the 10' etc," whereas elsewhere a highway isn't "the" 66, say, but just 66...presumably it's because "the 10" supplanted "the Santa Monica" etc etc...but I digress....

Maybe for reasons similar to explain why people from different geographic locales favor certain accents and pronunciations. One imagines that news and media coverage strongly influences how thoroughfares are shorthanded or nicknamed. (Picture Francis Powers, Kelly Lang, Lori Ross or Bill Keene giving live traffic reports.)

The Big Cheese tells me the southbound 605 is backed up all the way to the Foothill.

Between its west terminus in Santa Monica, California, and the major East Los Angeles Interchange, I-10 is known as the Santa Monica Freeway. The Santa Monica Freeway is also called the Rosa Parks Freeway for the segment beginning at I-405 (the San Diego Freeway), and ending at I-110/SR 110 (the Harbor Freeway). The segment between the East Los Angeles Interchange and the city of San Bernardino, 63 miles (101 km) long, is called the San Bernardino Freeway. Other names exist for I-10. For example, a sign near the western terminus of the highway in Santa Monica proclaims this highway the Christopher Columbus Transcontinental Highway.
The San Bernardino Freeway in California near the interchange with the Ontario Freeway (I-15)

I-10 is known to a considerably lesser degree as the Veterans Memorial Highway, and it is listed as a Blue Star Memorial Highway. In Palm Springs, I-10 is also named the Sonny Bono Memorial Freeway as a tribute to the late entertainer who served both as the mayor and as a U.S. Congressman. Another stretch a short distance east in Indio is proclaimed the Doctor June McCarroll Memorial Freeway. https://en.wikipedia.org/wiki/Interstate_10