Transport Minister Dean Nalder, or Mole-der as he’s been dubbed, has asked Main Roads to investigate the merit of building traffic tunnels under some of Perth’s busiest roads.

The Minister says tunnels under roads such as Canning and Stirling Highways would ease congestion in years to come, with Perth’s population set to hit 3.5 million people by 2050.

It’s the Transport Minister’s second proposal to use tunnels to improve Perth’s transport and traffic options.

Gary Adshead spoke to sustainability expert Peter Newman about the Minister’s proposal on the 6PR Morning Show.