David Drozd was driving to Dubbo with his wife and five of their children when their Kia Carnival was hit in the chaos following a head-on collision at Wallerawang on Friday, December 29. The driver of another vehicle, Jason McMahon from Narellan Vale, was also killed.

Tributes to Mr Drozd on social media have centred around his love of family and faith.

"He has left a legacy of a family who is full of so much love and support for one another, it's beautiful to see," Anita Peeters said on Facebook.

Ryan Connellan said that Mr Drozd was a "faithful member of Central Mountains Baptist Church". "He and his family would often attend conferences at my church. He was a lovely man who dearly loved the Lord and his family of nine children."

Mr Connellan said Mr Drozd and his family were on their way to Dubbo for the gender reveal of their first grandchild.

A GoFundMe page has been set up to help the family.

Mr Drozd was an experienced traffic engineer with a private consulting firm. He had previously worked for Penrith City Council for 15 years.

In urging people to support the GoFundMe appeal, Penrith City councillor Tricia Hitchen said Mr Drozd "spent many years of his life working to make Penrith a safer place for us all".

Blue Mountains mayor Mark Greenhill said the local community would rally around the family despite the pain of the tragedy.

"Our community will reel from the pain of this news. In the Blue Mountains we are very tight knit and the shock of this will affect so many," he told the Gazette.

"Life is so fragile and the most important parts of it are those we know and those we love.

"Our whole community will hold David and everyone who knew and loved him close to our hearts at this most awful time."

Posting on social media, Lithgow mayor Maree Statham extended her sincere sympathies to the "families and friends for the tragic loss of their loved ones" in the horror crash.

"To the remaining injured, including the beautiful children, our sincere concerns for your recovery, we have incredible specialists and medical staff in our hospitals that no doubt will fight the fight of their lives to do what they can to save these very badly injured patients."

Five vehicles were involved in the crash on the Great Western Highway, which happened just before 1pm, with injured passengers taken to Westmead Hospital and Westmead Children's Hospital.

Officers from Chifley Police District established a crime scene following the crash. A report will be prepared for the Coroner.