Cabin recently announced it had secured $3.3 million in seed financing for its sleeper-car buses. (I’ll explain that concept in a minute.) The funding was led by Founders Fund’s FF Angel, with participation from half a dozen other investors. This new round of funding will enable Cabin to expand its overnight transportation services regionally and nationally.

Now, about that “moving hotel” idea. A full-size travel bus has been outfitted with sleeping berths lining a narrow walkway, like trains used to have. There’s a small communal lounge area for social insomniacs, Wi-Fi for solitary insomniacs and earplugs and nighttime tea for all. There are attendants on hand and a bathroom on board, and each rider can bring two pieces of luggage for free.

Right now, there’s only one route between Los Angeles and San Francisco. Riders are picked up at 11:00 p.m. at a central location, and the bus arrives in the next city by 7:00 a.m. so you can make whatever meeting you have lined up. The price for an overnight ride is $115. One-way flights between those two cities are often less than $100, but with Cabin, you’re paying for a bed and the privilege of not having to fight over the armrest.

Cabin joins companies like Tesloop in creating shared long-distance road travel experiences that are intended to be nicer than, if not as fast as, airline travel. People seem to be interested; Cabin’s 2016 pilot project was called SleepBus, and it sold out all its tickets in three days. The wait list was 20,000 potential customers deep. That’s more than the estimated 15,000 people, according to Cabin, who fly between Los Angeles and San Francisco every day.