Police have told travellers to pack food and water, and that traffic could bank up for 20km at major check points.
Almost 314,000 people have now downloaded passes to enter Queensland, with borders to reopen at noon.
Premier Annastacia Palaszczuk says there'll be an indefinite ban on people travelling from coronavirus-hit Victoria, unless they can prove they've spent two weeks elsewhere before trying to enter Queensland.
"As long as it takes," she told the Nine Newtork on Friday, when asked how long Victoria would remain on Queensland's reject list.
"I hate to say that, but it's as long as it takes until the community transmission there is under control."
Police have told travellers making a beeline for the border to expect major delays over the next 72 hours.
"We anticipate extensive delays at the major checkpoints. These delays could be more than a couple of hours, with queues potentially up to 20km long," Tweed Byron Police Commander Superintendent Dave Roptell has told The Gold Coast Bulletin.
NSW school holiday-makers are expected to make up a large portion of incoming tourists.
Some northern and western NSW towns have reported dealing with a log-jam of caravaners waiting for Queensland to open up.
The money they'll spend will provide welcome relief for tourism operators and the hospitality sector, which have suffered huge economic losses during the 15-week border lock down.
Queensland's airports are also preparing for an influx of arrivals, but travellers will not be allowed to leave terminal buildings until restrictions officially ease at midday.
Some flights have been delayed to help avoid passenger traffic jams.
Virgin Australia has launched a major sale, offering more than half a million discount fares to Queensland destinations including Brisbane, Cairns, the Gold Coast, Hamilton Island and Townsville.
All arrivals into Queensland must hold a valid border pass, including residents returning to their home state.
People who've been in Victoria will only be allowed in if they have proof of a fortnight elsewhere first, such as dated accommodation receipts.
Queensland has only two active coronavirus cases and there's no evidence of community transition, the state's Chief Health Officer Jeannette Young said on Friday.
"I think we all need to commit that if any of us get any symptoms that we just immediate get tested, do our best to maintain social distancing, and that at this point in time, that we don't go down to Victoria or overseas," she's told ABC radio.
Victoria has more than 3000 cases, after days of triple-digit increases.
