The Opposition said data from public transport contractors showed there were almost 2,000 breakdowns in Adelaide in the year to last October.
Liberal transport speaker Vickie Chapman said nearly 200 trams and trains malfunctioned in that period.
She demanded the Government improve the reliability of services.
"Buses not running on time, sometimes complaints at their state of not just repair but also cleanliness, patronage is down, one in five aren't paying for the bus or train fares, these are all complaints that are coming on top of each other and now we find there's a situation of malfunction," she said.
Transport Department deputy CEO Emma Thomas said breakdowns affected a tiny percentage of the total services across Adelaide.
"In percentage terms it accounts for about 0.05 per cent of the services we operate in a year," she said.
"We operate 10,300 bus, train and tram services every weekday of the year.
"If you look at those numbers that a very, very tiny percentage of the overall services that we operate."