Deanna 'Violet' Coco, 33, and Bradley Homewood, 51, faced the County Court in Melbourne on Tuesday where they appealed their 21-day prison sentences for causing traffic chaos on March 5.
They were instead handed an increased sentence of two months, after Judge David Sexton found they "deliberately, flagrantly broke the law".
The rental truck was driven onto the middle of the bridge and blocked three lanes of traffic on the major Melbourne thoroughfare for more than two hours, causing major delays.
The pair, along with co-accused Joseph Zammit, climbed onto the truck, joined themselves together using pipes, set off flares, and unfurled an Extinction Rebellion banner.
Deanna 'Violet' Coco (centre) pleaded guilty to public nuisance offences. (Joel Carrett/AAP PHOTOS)
They were arrested after a police cherry picker was used to extract them from the truck, with Coco and Homewood jailed for 21 days by a magistrate on March 5, after they both pleaded guilty to public nuisance offences.
They both appealed, while Director of Public Prosecutions Kerri Judd launched her own appeal to increase their sentences as she said they were inadequate.
Crown prosecutor Jordan Johnston told the court on Tuesday that 26 police were called to the protest, at a "significant" cost of almost $8000.
He said 13 calls to police received a delayed response and three Ambulance Victoria calls were also impacted, including when paramedics were called to the bridge to help a woman give birth.
"This was clearly a well-considered plan in its location and timing. It was executed to effect maximum disruption at a major thoroughfare," he said.
A woman had to give birth on the side of the road, with the help of another person stuck in traffic, after an ambulance could not reach her due to lanes being blocked by the protesters.
Coco represented herself in court and gave a statement from the witness box where she apologised to the woman and her baby.
"When I saw this news from my cell I was devastated and I am so glad they are OK. Community safety is important to me and that is why I protest," she said.
"Reading the impact statement today has hollowed out my heart with grief."
She said she planned to change the way she protested in the future.
Homewood, who appeared via video link from prison, drove the truck onto the freeway.
His barrister Felicity Fox said he did not stand to gain personally from the offending, as she called for him to be released on a community work order.
Judge Sexton rejected this and decided the two protesters, who each have a history of similar offending, needed to be deterred.
He described the protest as "calculated to cause maximum disruption" as he increased each of their jail terms to two months.
"The offending occurred during morning peak hour, arguably the busiest time on one of Melbourne's busiest roads," the judge said.
"Whilst you may have been well intentioned or motivated ... the methodology you each employed to make your points caused significant risk and disruption to the lives of others.
"Your sustained obstruction of emergency workers was not appropriate and must be denounced."
Coco, who was taken to prison immediately, has already served 10 days of her sentence, and Homewood has served 14.
Co-offender Zammit was released on bail after the protest.
