American car companies sold more vehicles in 2015 than ever before, with sales boosted by low gas prices and a recovering economy — a remarkable turnaround from the recession years. But at the same time, GM is placing a bet on the industry’s next phase. It has announced an investment of $500 million in Lyft, the No. 2 car-hailing service (after Uber).
This is the first time a car company has directly invested in either Lyft or Uber, both of which foresee moving away from matching private drivers with riders to letting people summon driverless cars with an app. GM’s president, Dan Ammann, said that the focus of the partnership would be on developing...

