RTD: 1964-1975 (The First Decade)
On November 5, 1964, the Southern California Rapid Transit District (known by its acronym SCRTD, or the shorter "RTD" that appeared on buses, timetables, agency letterhead, and bus stop signage) assumed responsibility for the Valley service that had been operated by the LAMTA . However, some five years later, service was little different in the Valley since the MTA changes in 1962, with this 1970 map still showing a number of significant gaps where service had not yet been established:
(As a side note, this map was issued not long after RTD operators stopped making change for patrons as the "exact fare" rule was implemented October 12, 1969.)
Over the following half-decade, RTD took advantage of new tax revenue subsidies to fill in much of the Valley, but some arterial streets still were only served in sections, if at all. Service expansions were erratic and sometimes still left gaps in service on some streets.
The April, 1973 launch of Lines 139, 143 and 144 warranted a brochure promoting RTD's image as the family "ExtraCar":
The brochure also promoted an increase from hourly to half-hourly service on five key lines (14, 16, 74, 86 and 90).
This map shows service additions from September 1974 :
The dashed lines show the extension of Line 16 down Fallbrook Ave., a reconfiguration and extension of Line 139, and new Lines 180 and 182.
On March 2, 1975, RTD replaced the previous haphazardly-configured service with a grid of service that took better advantage of the Valley's geography. The red lines on the above map indicated the first four of the new "grid" lines -- 156, 161, 168, and 169 -- that began service on that date. (Line 24G was not a new line, but its service frequency was upgraded to the new "grid" standard on that date; Line 167 was a renumbered Line 15 which also upgraded in service frequency.) The black dots with what appear to be grey outlines actually are the line terminals, with arrows showing the direction of the turnaround loop.)