Why is it always Martin Luther King Blvd. Never a street, avenue, highway, by pass. Never Old MLK Blvd. Just MLK Blvd.
Wikipedia has a list of streets named after King. Most are boulevards, but there are also some avenues, expressways, etc.
Interestingly, the streets always feature his full name, and sometimes even his academic title "Dr." No one else gets this treatment. LA's main drag is Wilshire Blvd., not H. Gaylord Wilshire Blvd.; a major thoroughfare from LA to Whittier is Washington Blvd., not President George Washington Blvd., and a major street that runs through Compton is Rosecrans Ave., not Gen. William Rosecrans Ave.