A majority of American drivers say they would be scared to ride in a self-driving vehicle, according to a survey by the automotive organization AAA. However, the survey also found that people who already have semi-autonomous features in their vehicle are more likely to be comfortable with the technology.

Seventy-five percent of drivers polled by AAA said they would be afraid to have an autonomous vehicle drive them to their destination. Only 20 percent said they would trust an autonomous vehicle to drive safely.

"With the rapid advancement towards autonomous vehicles, American drivers may be hesitant to give up full control," said John Nielsen, managing director at AAA Automotive Engineering and Repair. "What Americans may not realize is that the building blocks toward self-driving cars are already in today's vehicles, and the technology is constantly improving and well-trusted by those who have experienced it."

Several automakers and other companies are working to develop autonomous vehicles and technologies. Many current models include semi-autonomous features, such as systems that maintain a safe following distance, warn a driver when they are drifting out of their lane, or automatically brake to avoid a collision.

Fully autonomous vehicles are still a work in progress. Automotive companies reporting to the California Department of Motor Vehicles said there were 2,788 instances where a human had to take over control from an autonomous vehicle during road tests between 2014 and 2015. Some of these disengagements were planned, but others occurred due to issues such as poor lane markings, inclement weather, unexpected maneuvers by other motorists, and safety concerns in construction areas or places with heavy pedestrian and bicycle traffic.

Google, which has been testing several vehicles on public roads, recently admitted that one of its autonomous vehicles bore some responsibility for an accident. The company says its self-driving vehicles have been involved in 17 minor collisions during millions of miles of road testing, and has blamed all of these prior incidents on human error in other drivers. In the accident on Feb. 14, one of Google's test vehicles ran into the side of a bus after its autonomous system expected that the bus would allow the vehicle to merge.

Concerns about autonomous vehicles varied by age and gender. AAA found that 82 percent of Baby Boomers said they would be afraid to ride in a self-driving vehicle, compared to 69 percent of Millennials. Women were also more concerned about the technology. Eighty-one percent said they would be afraid to ride in an autonomous vehicle, compared to 67 percent of men.

In addition to the worries about fully autonomous vehicles, respondents showed a lack of trust in semi-autonomous features. Lane departure warnings or lane keeping assist technology was the most popular semi-autonomous feature, but only 52 percent of respondents said they trust this technology. This was followed by 47 percent who trust adaptive cruise control, 44 percent who trust automatic emergency braking, and 36 percent who trust self-parking systems.

Men were more likely than women to trust certain systems. Forty-two percent said they would trust a self-parking system, compared to only 31 percent of women. Forty-nine percent said they would trust an emergency braking system, compared to 40 percent of women. And while half of the male respondents said they would trust adaptive cruise control, only 43 percent of women held the same view.

AAA's survey found that despite the concerns expressed by many drivers about autonomous vehicles and the split view on semi-autonomous technology, the latter features remain popular. Sixty-one percent said they would like to have at least one semi-autonomous feature such as adaptive cruise control, automatic emergency braking, lane-keeping assist, or self-parking capability on their next vehicle.

Eighty-four percent of respondents said they would want this technology to improve their vehicle's safety. Other popular reasons included convenience, cited by 64 percent of respondents; stress reduction, cited by 46 percent; and wanting the latest technology, cited by 30 percent.

Baby Boomers were most likely to cite safety when saying why they wanted semi-autonomous technology, with 89 percent giving this reason. Millennials were more likely to say they were interested in convenience or getting the latest technology, with 75 percent giving the former reason and 36 percent giving the latter. Half of the women in the survey felt semi-autonomous technology could reduce their stress on the road, compared to 42 percent of men.

One-third of Millennial drivers said they would like self-parking technology in their next vehicle, compared to only 22 percent of Baby Boomers and 20 percent of Generation Xers. The younger generation was also more likely to favor adaptive cruise control, with 45 percent of Millennials saying they would like this feature on their next vehicle. Only 37 percent of Generation Xers and 34 percent of Baby Boomers said they would like this feature.

Forty-four percent of men said they would like adaptive cruise control on their next vehicle, and 42 percent said they would like automatic emergency braking. By contrast, only 36 percent of women wanted the former feature while 35 percent wanted the latter.

People who already have semi-autonomous features in their vehicle were much more likely to trust it. Eighty-four percent said they trust their lane departure warning system, while only half of respondents without this feature said they wouldn't be concerned about it. Seventy-three percent said they trusted their adaptive cruise control system, compared to only 47 percent of those who didn't have this technology. Seventy-one percent trusted their vehicle's automatic emergency braking system, but only 44 percent of drivers without this technology thought it would work properly.

Drivers who did not want semi-autonomous technology on their next vehicle gave a variety of reasons for forgoing these features. Eighty-four percent said they trusted their own driving ability more than an autonomous system. Sixty percent believe the technology is too new and unproven, 57 percent did not want to pay the extra cost for the features, 50 percent did not know enough about the features, and 45 percent found the systems to be annoying.

Cost was the key concern for younger drivers and those with children. Sixty-three percent of Millennials, 62 percent of Generation Xers, and 65 percent of respondents with children cited the expense as a reason for not wanting to get a vehicle with semi-autonomous features. Only 53 percent of those without children and 49 percent of Baby Boomers said cost was a consideration in not wanting semi-autonomous features.

Women who did not want semi-autonomous features were more likely than men to say they were unfamiliar with the technology. Fifty-six percent said they did not know enough about the technology, while 23 percent felt it was too complicated. Among men who did not want semi-autonomous features on their next vehicle, 44 percent said they did not know enough about them and 12 percent believed they are too complicated.

AAA's survey collected responses from 1,832 adults in the United States between Jan. 14 and 24. The survey has a margin of error of 2.7 percent.