Self-driving cars are the future, we're told. But who's going to build them?

Probably not Waymo, the autonomous vehicle technology subdivision of Google's parent company, Alphabet. Waymo chief executive John Krafcik said in December: "We are a self-driving-technology company. We've been really clear that we're not a car company." Alphabet had profits of nearly $25 billion in 2016, and represents perhaps the best business model on the planet, with a quasi-monopoly on search and digital advertising, but its ambitions in the auto industry are more modest than they appeared a few years ago.

It doesn't look like it'll be Apple either. Initially determined to build its own vehicle, the company now is focusing on the software and hardware necessary to get a self-driving car on the road. Apple is the most profitable technology company in the world, with over $56 billion in profits in its most recent fiscal year. The company has $189 billion in net cash. Nobody has deeper pockets to invest in an endeavour like this, and yet it's not.

Uber continues to burn cash and might have more internal drama than any other company in America. It's hard to see this hot mess finding the capital and the focus to pivot from the existing business to producing automobiles at scale.

Tesla remains Silicon Valley's one hope for a self-driving car. Next year the company is aiming to produce 500,000 Model 3s, which have self-driving technology. But whether it is able to produce that many cars, whether demand is sustainable, and whether it can be profitable remains to be seen.

If an outsider is going to disrupt the automobile industry as transportation moves into a self-driving future, it needs three things: easy access to large amounts of capital, sophisticated technological capabilities, and desire. Silicon Valley has the first two in spades but seemingly lacks the third.

What started out as an industry driven by innovation is increasingly one infatuated by toll collection. In Apple's case, the Steve Jobs era was defined by transformational products, creating new product categories. The Tim Cook era is defined more by operational perfection, maintaining a supply chain, and ensuring that Apple collects a profitable toll every time consumers trade in for a new, slightly better version of the iPhone.

Google and Facebook want to collect a toll every time you run a search, watch YouTube or spend minutes on social media. They may spend some money on futuristic "moonshots," but their business model is collecting tolls.

Uber's still burning cash, but it's clear what its ambitions are: to monopolise ride-sharing and get a cut of every fare.

Apple, Google, Facebook and Uber have all made reasonable business decisions. Tolls are where the juicy profits are. Apple is far more profitable than Foxconn, its supplier that actually produces the iPhones consumers buy. Google and Facebook are far more profitable than the content and media companies putting in the work and taking risks on articles and videos that may or may not ever get clicked on. And operating a transportation network that takes a cut of every fare but doesn't have to own or produce vehicles or pay drivers salaries and benefits sounds like a pretty sweet deal too, if anyone can pull it off.

But someone's going to have to invest in the machinery and plants to produce the vehicles in a self-driving world. At the moment, the most likely candidates are companies not much more motivated than Silicon Valley: large incumbent auto manufacturers like Toyota, Ford and General Motors. The future of transportation will arrive whenever they decide to build it.

Bloomberg