Morley Safer - Correspondent:  Would n't it be nice , some people said , if Los Angeles had some streetcars ? Well , Los Angeles used to have some streetcars , a lot of them . Believe it or not , L. A. had the biggest and best streetcar system in the United States with over 1000 miles of track that hauled over 100 million people a year as early as _ 1920 _ .