SDER meaning in Regional ?

The San Diego Electric Railway (SDERy) was a mass transit system in Southern California, United States, using 600 volt DC streetcars and (in later years) buses.

The SDERy was established by sugar heir and land developer John D. Spreckels in 1892. The railroad's original network consisted of five routes: the Fifth Street and Logan Heights Lines, the First and "D" Streets Lines, the Depot Line, the Ferry Line, and the "K" Street Shuttle. The company would establish additional operating divisions as traffic demands led to the formation of new lines. The company also engaged in limited freight handling primarily as an interchange with Spreckels' San Diego and Arizona Railway (SD&A) from 1923 to 1929.

At its peak, the SDERy's routes would operate throughout the greater San Diego area over some 165 miles (266 km) of track. Steadily declining ridership, due in large part to the phenomenal rise in popularity of the automobile, ultimately led the company to discontinue all streetcar service in favor of bus routes in 1949. Some see this as related to the National City Lines's General Motors streetcar conspiracy controversy, as the SDERy's president had been with NCL previously.

The few surviving pieces of rolling stock are on display at the Pacific Southwest Railway Museum in Campo, the San Diego Electric Railway Association in National City, and the Orange Empire Railway Museum in Perris, California.