The companies have left hints as to what the partnership could entail. Lyft, for instance, has long said it wants to match its network of passengers and drivers with partners in the transportation industry. Last year, it struck a deal with General Motors, a major Lyft investor, to help with that goal. Under that agreement, the companies plan to test autonomous Chevrolet Bolt vehicles using Lyft’s network with the general public in the next few years.

Waymo has pursued its own partnerships. It is working with Fiat Chrysler on a fleet of minivans and is in talks with Honda about a possible deal that would put Waymo technology in Honda test vehicles. Waymo also recently introduced a pilot program in Phoenix in which consumers can apply to hail self-driving Chrysler minivans and Lexuses for free rides around the city. The company has said it hopes to find new ways through such partnerships to bring its self-driving technology to the general public after nearly a decade of development.

The seeds of the partnership between Waymo and Lyft were planted in discussions last summer, the two people familiar with the deal said. The talks involved Logan Green and John Zimmer, the founders and leaders of Lyft, and John Krafcik, the chief executive of Waymo. The idea of a deal evolved as the executives visited each other’s campuses in the ensuing months.

The partnership indicates that Waymo believes its self-driving-car technology has moved past the research stage and is ready to be applied commercially. Alphabet, Google’s parent company, spun Waymo out of Google’s X project lab in December after more than eight years of research. The vehicles have been tested on closed tracks and open roads in Arizona, California, Texas and Washington, where state law allows the testing of autonomous vehicles. Waymo has said the vehicles have logged more than three million miles of real-world testing.