The 28-year-old died on the Pacific Motorway at Loganholme, south of Brisbane, after pulling over following a minor rear-end crash in afternoon peak hour traffic.
Two vehicles had stopped in the northbound lanes to exchange details when she was hit by dual-cab utility as she walked back to her car on Monday, police said.
She suffered catastrophic head injuries and could not be revived. The ute driver is assisting police.
Premier David Crisafulli described the incident as "an incredibly tragic situation".
"That is just a really sad and tragic set of circumstances," he said on Tuesday.
"Our thoughts go with her family, everyone involved, including emergency services."
The deadly crash came as severe storms hammered Queensland's southeast from Bribie Island to Coolangatta, triggering flash flooding and soaking the Gold Coast with up to 160mm of rain.
In the Scenic Rim, swift-water crews and SES volunteers used a boat to ferry almost 50 people – including 42 Year 12 students and teachers from North Lakes State College – across a flooded road after their school camp at Mount Barney was cut off.
The deluge was driven by a rain band and a coastal trough combining over the region, the Bureau of Meteorology said.
"We've had a rain band extending from the northwest, as well as a coastal trough combined to bring significant and unseasonable rainfall to parts of southeast Queensland and extending into northern NSW over the past couple of days," senior forecaster Ilana Cherny told AAP.
"Those heaviest falls were really on Monday and overnight into Tuesday morning as well, with those highest falls around the Gold Coast and Border Ranges area."
Minor to moderate flooding has been reported across multiple Gold Coast catchments, with river levels elevated on the Pimpama and Coomera rivers as well as Mudgeeraba Creek.
Warnings are also in place in northern NSW with minor flooding likely at Lismore from around midday on Tuesday.
Low-lying areas, crossings and flood-prone farmland remain at risk, with drivers urged to take care as the system eases and shifts offshore.
"We're expecting a little bit more shower activity today, but the heaviest falls have passed," Ms Cherny said.
A cool change will follow, with temperatures forecast to sit two to six degrees below average across much of central and eastern Australia for the rest of the week before edging back towards normal by the weekend.
Residents have been urged to stay clear of swollen rivers and creeks and to monitor the latest warnings.
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