Golden Arrow Bus Services spokesperson Bronwen Dyke-Beyer said a total of 22 buses were stoned on Friday alone.
The bus company has had 14 buses torched since last year with latest incident occurring in Malibu Village last week.
Golden Arrow calls on government to help protect passengers as buses continue to be targeted by criminals
Cosatu has asked the bus company to give details on their safety plan.
“At this stage an investigation is underway into exactly what transpired and what action should be taken. This is an unprecedented situation and a number of factors have to be taken into consideration. Passengers should not under any circumstances, no matter how well-intentioned, attempt to drive a bus,”
The project has an estimated lifespan of 20 to 25 years and projections indicate financial savings of more than R80-million over its lifespan.