Elon Musk has a plan to solve the traffic crisis in our cities. A vague, secret plan. He may not actually have a plan. But he did say something out loud in public about it, and he doesn’t usually do that unless he has at least kind of a plan.

Bloomberg reports that, speaking at a transport conference in Norway, Musk’s fecund imagination briefly overflowed. “We have an idea for something which is not exactly a bus but would solve the density problem for inner city situations,” he said. “I don’t want to talk too much about it. I have to be careful what I say.”

He also said that “there’s a new type of car or vehicle that would be great for that and that’ll actually take people to their final destination and not just the bus stop,” adding that “autonomous vehicles are key.”

I could speculate about what it is, but — actually, why not?

A “new type of car or vehicle” that “is not exactly a bus” but would drop you off where you’re going. So it uses city streets, isn’t quite a car, and benefits especially from autonomy.

To me, that sounds like an 8-10 passenger EV that automatically picks up and drops off multiple users on shared routes. This would be something about the size of an airport parking shuttle, with room to stand and stash your suitcase or bags of groceries. For longer rides they could even hook up for aerodynamism and (why not?) allow people to switch cars — a true road train. Smaller vehicles that hook up with others into a little autonomous vehicular centipede might also be a possibility.

Of course, no one really likes shuttles, because they make so many damn stops. But if the route and passengers were carefully calculated according to citywide efficiency systems, it wouldn’t be so bad. Anyway, that’s my guess.

The only person who really knows is Musk and whoever he’s spilled the beans to. The best thing to do now is to alternately badger and butter up this genius billionaire until he publishes a big paper on it. Worked for the Hyperloop!

“I wish I had not mentioned it,” he said at the time, in an interview with Businessweek. “I still have to run SpaceX and Tesla, and it’s fucking hard.”