Jim Flack will be completing the Rimutaka Crossing re-enactment in honour of his relatives.
"Two generations of my family dropped what they were doing and answered the call ... I'm delighted to live in a world where we are not required to answer the same call."
Thanks to a diary kept by his grandfather, who trained at the Featherston Military Camp in 1915 before serving in Egypt and France, Mr Flack got a glimpse into what it was like to be a soldier in WWI.
He said reading the diary made him feel as if he got to know his grandfather, Vern Chapman, who died before he was born.
Mr Flack said Vern didn't sign up immediately as one of his brothers, Sid, went to Gallipoli and never made it back.