The risk of hackers taking control of an autonomous vehicle is what concerns people most about technology that will allow future vehicles to drive themselves, according to a survey conducted by insurance company American International Group Inc.

Three-quarters of those polled feared hackers could gain access to the control systems of an autonomous car, presumably with the intent to use the vehicle to cause harm.

Respondents also said they don’t expect driverless cars will be on the road within the next 20 years, despite assertions by many automakers that many vehicles will be equipped with self-driving technology by 2020.

If the average driver is both a bit hopeful and fearful about self-driving cars, they’re not alone: The insurance industry is figuring on autonomous vehicles causing a major disruption by 2040 if insurers don’t find ways to adapt to what could by then be a new reality.

And despite that fear of hacking, 39 percent of people said they thought autonomous vehicles would work more safely than the average human driver. The survey also revealed little is known about where blame would lie in the event of a crash involving a self-driving car: Responses suggested liability could be placed on the car’s manufacturer, the company that produced the self-driving software, or the human inside the vehicle.

For its part, AIG foresees risk shifting from humans to machines—but certainly not disappearing.

While 35 percent of people felt self-driving cars could reduce insurance premiums, a study by AlixPartners said the majority of U.S. consumers are unlikely to buy a self-driving car when they first come to market.

(via Bloomberg)