General Motors’ autonomous vehicle subsidiary Cruise has always lived in the shadow of Alphabet’s Waymo unit, which was first to launch a robotaxi service late last year. But under new CEO Dan Ammann, who was president of GM until a month ago, Cruise is hoping to prove it can be among the first to build a robotaxi business in a dense urban center, starting this year.

The 46-year-old Mr. Ammann, a onetime Morgan Stanley investment banker who has been with GM since 2010, will need to tap more experienced managers to run Cruise. The company has fallen behind some of its early ambitious targets for road-testing its prototypes and launching a service to the public. Cruise has more than doubled its headcount in the past year or so, to nearly 1,200, including nearly 900 engineers, according to data viewed by The Information.