https://medium.com/kylevogt/why-testing-self-driving-cars-in...
GM right now is the most vertically integrated of all the companies making meaningful progress on Robotaxis. They have a dedicated assembly line set up building off the Chevy Bolt platform, and intend to have 'thousands' of them on the road before the end of 2018. They're building their own ride hailing app, called Cruise anywhere, currently only available to GM employees. They've got On-star, which provides in-house expertise with connected car and vehicle diagnostic services. GM's Maven subsidiary offers car sharing services.
But when Robotaxis really proliferate fleet management infrastructure will be very important. Apple and Waymo have made partnered with Hertz and Avis respectively, but General Motors can utilize the real estate and expertise of it's existing network of dealerships, which can save them from a great deal of capital investment as Robotaxis dissemintate.
Before last December there wasn't a whole lot to be known about Cruise's progress, but since then it's just been one reason after another to be getting excited about what they're doing.