The first analyst question at Berkshire Hathaway's annual meeting on Saturday was about the threat of self-driving technology.

"If they make the world safer it's going to be a very good thing, but it won't be a good thing for auto insurers," Buffett said.

Self-driving cars have moved from a futuristic dream to a technology that corporations from BMW to Alphabet and Apple are investing in. Buffett said he thinks widespread adoption of self-driving cars is further down the road, and will depend on how safe they are outside test situations.

"If driverless cars became pervasive it would only be because they were safer," he said. "That would mean that the overall economic cost of auto-related losses had gone down and that would drive down the premiums" for companies like Geico, a Berkshire wholly owned subsidiary.

"The driverless trucks are a lot more of a threat than an opportunity to Burlington Northern," Buffett added.