Victorians can now freely enter South Australia.
Border restrictions have been scrapped to allow free travel between the two states for the first time since March.
South Australian police commissioner Grant Stevens said Australia had "virtually eliminated" COVID-19, and there was no longer reason for border restrictions.
"The online approval process for people travelling within Australia coming into SA will no longer be required," he said.
"We will no longer be stopping vehicles and speaking to drivers (at road checkpoints).
"There is no restriction or impediment."
Commissioner Stevens said police would be scaled back at the state's borders.
"We imagine this ... will be a relief for people travelling across the border via road, and gives us the opportunity to redeploy our officers back to other duties," he said.
"We do have infrastructure we need to maintain security over so as we scale down that infrastructure, we'll be bringing our people back over the next few days."
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