Parent Allison Hugo has seen Sherwood Ridge Public School grow from about 100 pupils to more than 840 in the past 10 years, and traffic problems with it.
The Kellyville school is not immune to the kiss-and-drop zone woes that plague schools in the area, with illegal U-turns and congestion among the complaints of parents and police.
"I think people's knowledge and understanding of how they should work is a major factor," Mrs Hugo said.
"A lot of the time they see their child waiting and duck in to get their child but it's not following the process and doing it the right way, the safe way.
"The area is built out; there's not sufficient parking. They've put in lots of no-stopping signs which I understand can help the residents, but because the school has grown there are more teachers and they don't fit in the car park.
"They then park on the streets and take up parking that's available for parents. It's adding to the frustration of it all."
A Hills Council spokesman said the popularity of kiss-and-drop zones in The Hills meant it was not uncommon to see queues forming more than 30 minutes before the school day finished.
"The council has reminded parents that this practice has a negative impact on safety and traffic around school zones during the afternoon peak," he said.
"It is far safer for parents to park their car and walk to the school to pick up their children."
The spokesman said Sherwood Ridge's school zone was not "particularly problematic" compared with other Hills schools.
He said 21 infringement notices were handed out by council rangers there in the past six months, with the two most common offences disobeying no-stopping signs and stopping in a bus zone.
Hills crime manager Detective Inspector Gary Bailey said police had ongoing operations to curb bad driver behaviour during school pick-up and drop-off times.
He said police expected the co-operation of parents.
"As soon as we move away we know people don't abide by the rules," he said.
"We can't be at every school every day but we do pour resources into it because we realise the dangers.
"We can only keep trying."