Multi-CEO and future builder Elon Musk may have been so frustrated by sitting in traffic that he’s going to start yet another company – a boring one. Yes, boring – as in boring tunnels, using machine diggers to create undercut routes to alleviate surface traffic.

Musk tweeted Saturday about being struck by inspiration for this new venture, making a series of “boring” puns before tweeting a seeming confirmation that he’s actually going to take this on as a serious pursuit:

I am actually going to do this — Elon Musk (@elonmusk) December 17, 2016

The Tesla and SpaceX CEO is prone to goofs, but he’s seldom been known to troll quite so hard as to say outright that he genuinely wants to do something in quite this way. Musk also changed his Twitter bio to include “Tunnels (yes, tunnels)” alongside Tesla, SpaceX and OpenAI as his current pursuits.

Here’s the thing about these tweets – they sound like a pretty juvenile response to encountering traffic; you’re average imaginative teenager has probably come up with two scenarios for getting around it: A) flying cars, and B) tunnelling under. But Musk’s reputation means he might actually have put some genuine thought into this from a feasibility perspective, and at least conceived of some kind of rough roadmap.

If, that is, he isn’t just massively trolling as part of his unpredictable and unfiltered Twitter persona. For what it’s worth, I think he’s being genuine – and that means one more huge mountain to climb – or in this case, dig under – for tech’s most ambitious impresario.