A new self-driving car initiative in the Tennessee Legislature has positioned one of the nation’s top automakers against Silicon Valley heavyweights, as both camps attempt to be among the first to develop and commercialize autonomous vehicles.

Sponsored by Sen. Mark Green (R-Clarksville) and Rep. Will Lambreth (R-Cottontown), the SAVE Act, if passed as it currently stands, would allow car manufacturers to run pilot programs for fleets of on-demand, self-driving cars in Tennessee. Detroit-based…