Bill Gates says he's not sure Elon Musk's Hyperloop concept makes sense

Bill Gates participated in a Reddit AMA on Tuesday and discussed a range of topics, including transportation. After a user asked Gates why the Gates Foundation hasn't paid much attention to transportation, Gates said that the private sector "rewards innovation in this space quite well," and expressed optimism about electric and self-driving vehicles.

"I think electric cars and autonomous vehicles will be great things," he wrote.

Gates then cast doubt on Hyperloop, Elon Musk's proposed high-speed transit system.

"I am not sure the hyperloop concept makes sense — making it safe is hard," Gates said.

Gates didn't elaborate on the safety issues surrounding Hyperloop and how they will be difficult to solve, but it's easy to see where he may be coming from. First proposed by Elon Musk in a 2013 white paper, Hyperloop would place people in pods and send them through tubes at speeds that could exceed 500 mph.

Elon Musk's Boring Company is attempting to build tunnels that could one day house a Hyperloop system.

Aside from the safety concerns that could arise from traveling at exceptionally high speeds, Hyperloop would likely rely on a network of underground tunnels that have yet to be built. While Musk's tunneling company, the Boring Company, is trying to build that network, it will need to secure the approval of a large number of local governments. (Some have given approval for test tunnels, others have been skeptical.)

Other figures in the transportation industry, like former Delta CEO and current Amtrak CEO Richard Anderson, have cast doubt on Hyperloop. Anderson said Hyperloop wasn't "realistic right now" in September and said infrastructure investment should be focused on repairing bridges and tunnels.

(BUSINESS INSIDER)