"One of the drivers even carries a potty - it's not used when there are passengers on the bus - the contents go into the gutter."
But Mr Froggatt said that was no good to a driver who told the court he had an upset stomach and diarrhoea before he left his bus at a stop in Dominion Rd, Mt Roskill, and rushed to a toilet around the corner.
Although the driver lost, and was fined $60 with $30 court costs, his employer had since agreed to cover the penalty and consider other cases on their merits.
Mr Froggatt said another driver, fined for stopping on broken yellow lines next to a full-up bus stop in Queen St to let off a disabled passenger with a wheelchair, had Auckland Transport's case against him dismissed in court.
He called on AT to support the union in lobbying the Government to change legislation to allow buses to be left unattended in emergencies.
Auckland Transport spokesman Mark Hannan confirmed the union had raised the issue with it, and that AT had in turn asked bus companies if they considered it a problem for their drivers.
"Obviously we want to work with the companies and the union in the best interest of drivers to ensure their comfort," he said.
Mr Hannan said parking officers generally waited about five minutes before issuing tickets at bus stops.
"But the last thing we want is unattended buses blocking stops while other buses have to queue or double-park to let off passengers."
Several areas, such as in Beaumont St next to Victoria Park, had been set aside for bus parking so drivers could get food or go to the toilet.