Why GM and Waymo Rely on Allies in Self-Driving Race

An automaker like General Motors Co. brings two advantages to the development of self-driving vehicles: knowledge of how to build a car, and the factories to do it. Silicon Valley’s biggest entrants into autonomous vehicles, particularly Alphabet Inc., have legions of coders and piles of cash. Now GM and Alphabet have found someone else to handle the aspects of this historic undertaking that the companies are least adept at doing themselves.

Carmakers hate risking billions of dollars more than they do already to compete in a low-margin industry, and so SoftBank stepped forward May 31 to drop $2.25 billion into ...