Create some clean green cycleways

There are close to 160,000 toxic sites in Australia

at the very least they should keep away from old railway lines, which are poisoned with herbicides and pesticides that include arsenic

The main message for Australians is to be aware of the danger of toxic substances in the air and to be aware that contaminants are present where ever there are old railway tracks

They could always clean them up by doing what NZ did to all those miles of contaminated railway ballast. 

Turn them into "shovel ready" make work schemes cycleways that the nice Mr Key promoted heavily near the beginning of his 'evil' reign. 

I'd bet there was zero testing of the ballast for DDT residues and the like prior to its new 'clean green' usage.  I see a good job in testing for a DOC bludger to pursue something useful.  Hell, maybe even the most recently discarded lines like Gisborne-Napier and the union infested Hillside workshops could be tested.