Killed: from left, Casey Valetic, Melissa Parry and Brad Dickson. Sarah Houlihan, 32, of Roxburgh Park, was behind the wheel of the dark-green BMW. Assistant Commissioner Jack Blayney said other drivers had contacted police after narrowly avoiding the BMW, but the crash occurred near the Avalon Road overpass as police from the Lara station rushed to the scene. ''It is an extreme situation. We've got someone driving in the wrong direction down the freeway. Anyone can imagine how horrific that might be,'' Assistant Commissioner Blayney said. ''In terms of road safety, there is very little we can do in these situations. It's just a very, very sad circumstance.''

The wreckage of the vehicle containing six passengers. Credit:Justin McManus The crash site was one of the most distressing police had seen, he said, comparing it with a crash in Penshurst in south-western Victoria last year in which five young people died. ''It's had a huge impact on the emergency services and members of the community also who are driving past and can see with their own eyes,'' he said. The vehicle is removed from the scene. Credit:Justin McManus Assistant Commissioner Blayney said it could be weeks before investigators established whether drugs or alcohol had contributed to the crash.

He said the number of passengers in the Melbourne-bound car ''did not match the number of seatbelts in the back''. Flowers at the crash site. Credit:Wayne Hawkins Last night, Jamie Valetic, 21, paid tribute to her older sister Casey, saying said she had lived for her daughter, Annabelle, who will turn two in February. ''I feel terrible for Annabelle. She will have the love of her two grandmothers and her aunts and the whole family, but she will never know her mum. And that's the bit that none of us can deal with,'' she said. Ms Valetic said her sister had lived life to the full before it was tragically taken away.

''Everyone loved Casey, she was crazy and wild and loved life,'' she said. ''She took advantage of everything, but it's all come down to a random woman on the wrong side of the road.'' Ms Valetic said the group had met at the Park Hotel in Werribee before heading to a Geelong bar later in the evening. Ashlee Mence, 21, received a text message from her best friend, Melissa Parry, at 11.40pm on Friday, just before the crash. She said she was still in shock after delivering flowers to the crash scene. ''She was such a positive person. She wanted to travel Europe by herself, buy a house and open her own gym with a beauty salon for tanning and nails,'' Ms Mence said.

Friends of Sarah Houlihan paid tribute on Facebook to a ''beautiful girl'' with a ''beautiful heart and soul''. On Wednesday, Ms Houlihan changed her Facebook cover, with a picture of a white wolf and a quote from motivational speaker Steve Maraboli: ''My past has not defined me, destroyed me, deterred me, or defeated me; it has only strengthened me.'' Sergeant Dan Willsmore, of Corio police, said police were aware that motorists drove on the wrong side of the Princes Highway regularly, as often as once a week. Over the past decade at least six other motorists have been killed by vehicles driving on the wrong side of the busy stretch of highway between Melbourne and Geelong. ''They are sometimes foreigners or tourists coming from overseas or they just make a mistake,'' Sergeant Willsmore said.

''It is not that hard to see how they do it on the overpass, but mostly they click and get into the right side.'' Loading Victoria's road toll now stands at 266, four fewer than the 2011 toll of 270.

Police have appealed for anyone who may have seen the vehicle travelling in the wrong direction or witnessed the crash to call Crime Stoppers on 1800 333 000 or visit crimestoppers.com.au