After a closely watched vote, driverless cars, once a Silicon Valley fantasy, have become a 24-hour-a-day reality in San Francisco. Are autonomous vehicles an interesting and safe transportation alternative? Or are they a nuisance and a traffic-blocking disaster waiting to happen?Cade Metz, who covers technology for The Times, describes the unique challenges of coexisting with cars that drive themselves.Guest: Cade Metz, a technology correspondent for The New York Times.Background reading: 

• On Monday, Waymo began letting the public pay for rides in its driverless cars in San Francisco. The New York Times dispatched three reporters around the city to test the service.
• Local officials are worried that state regulators have been too eager to embrace plans for round-the-clock driverless taxi services.

For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.