The company has switched its target from 100 self-driving vehicles to 100 people participating in the program over the next four years.

Volvo has reportedly scaled back its ambitious plan to launch an autonomous-car pilot project, known as Drive Me.

The company initially promised to launch a fleet of 100 self-driving cars near its headquarter city of Gothenburg, Sweden, by 2017. The vehicles would have been used on select roads by local residents.

A press release issued this week suggests the program has only reached two families. Both will use the XC90, presumably modified with data monitoring equipment but no prototype Level 3- or Level 4-rated autonomous drive systems.

"Both families will contribute to Drive Me with invaluable data by allowing engineers at the company to monitor their everyday use and interaction with the car, as they drive to work, bring the kids to school or go shopping for groceries," the company says.

The automaker now plans to add three more families early next year, with up to 100 participants invited in the next four years.

The data will be used to make a fully autonomous car commercially available by 2021.