The executive suggests the 'promising' talks involved a tunnel network that could benefit bikes, cars and pedestrians.

Tesla CEO Elon Musk's Boring Company tunneling startup appears to have caught the attention of Los Angeles Mayor Eric Garcetti.

A Santa Monica city manager earlier this month dismissed Musk's subterranean ambition as a "completely absurd pipe dream" that would be laughed out of the permitting office.

A vocal critic of California's notorious red tape, Musk apparently launched a lobbying campaign to support his idea that tunnels could help mitigate "soul-destroying" traffic.

"Promising conversations with @MayorOfLA regarding tunnel network that would carry cars, bikes and pedestrians," Musk wrote on Twitter, noting that permits are going to be "harder" than the technology.

The reference to bikes and pedestrians meshes with Boring Co's vision for small diameter tunnels paired with autonomous electric skates. The platforms can be used to ferry cars or enclosed passenger pods at 125 mph. Such an infrastructure system is promoted as a stone's throw from a Hyperloop, launching passengers through tunnels at more than 600 mph in a vacuum.

The startup has already started digging in Los Angeles County, however the prospective tunnel network has not yet breached the perimeter of SpaceX's parking lot.