People are also waiting days for results, upsetting travel plans and leaving potential COVID-19 sufferers confined.
State Secretary for the Health Services Union, Gerard Hayes , told 2GB radio COVID-19 testing sites are being packed because people are required to get tested before they go on holiday.
While he acknowledged that no testing system ” is ever going to be perfect”, he said that there could be “easier and better ways” to be handling the huge demand.
“I think it’s a ridiculous situation, and something should be done about it,” he said.
Mr Hayes added healthcare workers have been “been chronically fatigued for 18 months”.
“We’ve now got a new version of the virus and we’ve got to be fit for purpose for 2022. And I don’t think that we’ve been doing [that] up until now,” he said.
The clinic on Plough Inn Road at Leumeah in Sydney’s south-west has already closed, with police warning people to avoid it.
Barriers have also been erected at a clinic at nearby Liverpool, before mid-morning.
Further north, cars are also being turned away at Adcock Park in West Gosford.
At Coffs Harbour, some people have been queueing since 11pm yesterday, making the choice to sleep in their car rather than risk missing out.
Hundreds of cars are already lined up, with health authorities urgently requesting help from SES for traffic management.
Police have also warned that the testing clinic at Cessnock in the Hunter Valley would be closing at 11am today.
Navodhya was one of the many who was turned away from the Parramatta Western Sydney University COVID-19 testing clinic this morning.
“We got there at nine and the line was blocking the road. It was like all down the road. I couldn’t even see where the start [of the line] was,” she said.
A police officer told Navodhya she wouldn’t be able to get a test as the clinic was closing at 12 due to reduced hours and had already reached capacity.
“It was annoying because we just knew we wouldn’t be able to go anywhere else,” she said.
Like many people around the country trying to get a test before going away on holidays, Navodhya said it’s left her feeling a little apprehensive.
“I think if we didn’t have pregnant friend coming with us I’d be probably more okay just using the [rapid] test. It’s a bit concerning that we can’t be extra safe for her sake to get that proper test.”
Queues also began early in Melbourne, where congestion has overwhelmed testing centres in recent days.
The state government is considering allowing asymptomatic people to clear themselves with a rapid antigen test at home.
If it returns a positive result the person will need to queue for a PCR test, but it’s thought that the decision would ease pressure on health workers.
Hundreds of Queensland health workers are also struggling to get a test, telling 9News they were having to queue for hours.
So far, 55 health workers have tested positive for COVID-19, while a further 300 are in isolation.
Wait times in Queensland were around five hours.
Currently, Queensland and Tasmania are the only states to require a negative PCR test for incoming travellers.
Even after spending hours in a queue – assuming they get there early enough – there’s no guarantee of a quick result.
Wait times of up to six days and counting have been reported by frustrated people.
In Queensland, the average wait time for results was 72 hours.
The delays are being blamed on the excessive queues – though Queensland Premier Annastacia Palaszczuk said today that the closure of private providers during the holiday period had added to the pressures on health workers.
In New South Wales, police have urged people to not get tested unless they have symptoms or have been directed to do so by authorities.
There have been cases of people being turned back at the Queensland border, due to their test results not coming through in time.
An expert in COVID-19 testing says the mistake which saw 400 people given the wrong test results shows rapid antigen testing needs to be rolled out to relieve the pressure on PCR sites.
Histopath’s operations director Greg Granger, who used to work at SydPath, which was responsible for the blunder, said the mistake shows the system is “overwhelmed.”
“I can certainly confirm that the pressure is overwhelming and that alternative sources need to be found,” he told Today.
“The rapid antigen testing is one that comes to mind.
“I can say with complete authority the systems they have there are entirely robust and the team in microbiology are world class.”
He said pathology staff worked over Christmas and even if more sites were added, there wouldn’t be staff to man them.
“This extraordinary demand is only going to get worse,” he warned. “It is of concern for me. And it really should be a concern for the entire sector.”