 In the 1930s and 1940s , the Western Australian Nomenclature Advisory Committee had been choosing directional names for the state 's main arterial roads ( such as Great Eastern Highway ) , while the South Australian Highways Department had been naming the major roads to other states after explorers ( such as Flinders Highway , named after Matthew Flinders ) . The historical memorials committee of the Royal Geographical Society in South Australia was disappointed in 1938 that no road had been named after Eyre , despite its suggestion that the road from Port Augusta towards Perth should be Eyre Highway . In the same year , the RAC suggested that the proposed new highway be named Forrest Highway , after John Forrest , and the Assistant Minister for Commerce , Senator Macdonald , concurred . 
