"To meet these challenges, auto companies must implement suitable methods and measures for software development to manage quality and mitigate risk," Riccetti said.
It's not the first time Americans who might be offered the chance to buy driverless vehicles have expressed strong reservations about the technology.
According to a recent survey by CarInsurance.com, 20 percent of Americans said they would turn in their keys if they had to drive only an autonomous vehicle. The study also found that many motorists would be more willing to consider driverless technology if they were offered insurance discounts.
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On the other hand, a survey by automotive consulting firm Accenture, released last month, found about 90 percent of American motorists are interested in driverless technology—or at least some of the features that are already beginning to show up in today's vehicles. These include automatic braking systems that can stop a car in an emergency, auto-parking systems and lane-keeping technology.
(Read more: US eyeing car-to-car communication)
Nissan has promised to put its first fully autonomous vehicle into production by 2020, and several other makers, including General Motors' Cadillac division, are targeting similarly aggressive goals. Several other manufacturers, including Toyota, have expressed skepticism, however, and are looking only to add more advanced safety features, such as auto-braking, which would continue to leave a human driver in charge of operating the vehicle.
—By CNBC Contributor Paul A. Eisenstein. Follow him on Twitter @DetroitBureau or at thedetroitbureau.com.