As the ABC celebrates its 90th year, Heather Ewart takes a look at the evolution of the great Australian road trip, and revisits some of the very best she's taken on Back Roads.

There are unexpected encounters when colourful South Pacific and traditional cultures kick up the red dust of the Pilbara, as the team head to the town of Tom Price in Western Australia.

Guest presenter Joe O'Brien taps into his inner Bear Grylls in this Back Roads adventure to Cradle Mountain in the wilds of the Tasmanian Highlands.