Street names have changed over the years in Los Angeles. Knowing the old as well as the new names is important to the transit historian. For example, While many people know that Martin Luther King Bl. used to be known as Santa Barbara Ave., fewer know that Broadway south of Downtown was originally named Moneta Ave.
A few recommended sites:
Los Angeles in the 1900s: Streets of a Hundred Years Ago by George Garrigues (http://www.ulwaf.com/LA-1900s/SpecialReports/Streets.html). Based on a 1903 Chamber of Commerce map.
“Street Names: Are They Sacred?” (Bottleneck Blog, Los Angeles Times)
Rasmussen, Ceciia. “The Long and the Short of the Southland’s Street Names” (Los Angeles Times, December 10, 2006)