Complex sentence: Santa Clara County Supervisors opted out in 1957, preferring instead to build expressways, and in 1961 San Mateo County supervisors voted to leave BART, saying their voters would be paying taxes to carry mainly Santa Clara County residents.
Split into simpler sentences: Santa Clara County Supervisors opted out in 1957, preferring instead to build expressways. In 1961, San Mateo County supervisors voted to leave BART, saying their voters would be paying taxes to carry mainly Santa Clara County residents.