Jesse Levinson, co-founder of and chief product officer at the Amazon-owned robotaxi Zoox, and his team are betting that the vehicles’ pod-shaped design will be the preferred shape of future autonomous transportation.

The start-up is testing its technology on roads across six US cities with plans to launch commercially this year in Las Vegas, followed by San Francisco. The vehicles have no steering wheel and four inward facing seats.

Based in San Francisco’s Bay Area, Levinson has been working on self-driving vehicles for about two decades. He developed algorithms for the runner-up entry in the 2007 Darpa Urban Challenge, the driverless car contest sponsored by the US Department of Defense that helped spawn Google’s self-driving unit Waymo, before founding Zoox in 2014.