In guide to roadfood must include the Harris Ranch just off the I-5 near Coalinga (birthplace of Jo Stafford). Harris Ranch is actually the only decent place to eat on the I-5 and it's about half way between LA and the Bay Area.
Yes, it is touristy but the food is excellent. It is a working ranch and as you drive north from Harris you can see the vast herds of cattle waiting to be transformed into steaks and roasts. The beef is outstanding. In addition, there are a range of other selections, including fish and great Tex-Mex dishes like fajitas. For those who want to buy as well as eat, you pass a butcher store and a small produce stand as walk along the corridor to the restaurant. The produce is good but can be a little more expensive than elsewhere. There's also a bakery that sells spectacular fresh fruit pies and other goodies.
Dress is casual. Most of the people eating are in the state uniform of California--T-shirt, shorts and sports shoes or flip-flops.
Roadfood really should recognize the vast array of really authentic ethnic restaurants in California. We don't just have Chinese restaurants. We have restaurants from every region and culture in China: Shanghai, Beijing, Shantung, Muslim, Hakka, Taiwan, Szechuan and many others. A lot, but now all are listed in a great book called "How to Eat in Chinese in Los Angeles." We have restaurants from every region in Mexico and Latin America, other parts of East and South Asia and the Middle East. Another great book is Jonathan Gold' "Counter-Intelligence" that describes a lot of the ethnic restaurants as well as some basic American restaurants. Some of these places are classy others are dives or someplace in between.
I live in Glendale. We have the largest Armenian population outside of Armenia. This population comes from all over the Armenian diaspora and the food they produce is wonderful. Zankou Chicken which features spit-roassted chicken and a blinding white garlic sauce that will have you smelling of garlic for a month is one of the best. But Carrousel is first-rate.
And we also have Porto's, which many of us consider the best Cuban bakery and restaurant west of Tampa. It started as a small bakery but has expanded into a large restaurant and once you taste the media-noches or the chicken croquetees or the croissants (Cubans have always loved French food) you will know why.
If anyone is planning to come to Southern California and would like restaurant recommendations feel free to contact me. Stanton J. Price email@example.com