A growing number of Americans are becoming less squeamish about the possibility of a vehicle that drives them instead of vice versa, according to a recent study by AAA.

The automotive organization conducts a survey each year to see how drivers' attitudes toward autonomous technology might be changing. In the latest survey, a majority of respondents—63 percent—were still afraid of riding in a completely self-driving vehicle. However, this share was down significantly from 78 percent in early 2017 and 75 percent in early 2016.

"Americans are starting to feel more comfortable with the idea of self-driving vehicles," said Greg Brannon, AAA's automotive engineering and industry relations director. "Compared to just a year ago, AAA found that 20 million more U.S. drivers would trust a self-driving vehicle to take them for a ride."

Although a large number of people remain leery of the idea of a fully autonomous vehicle, many automakers have been working to develop this technology. Most manufacturers are aiming to have advanced autonomous technology, such as vehicles capable of driving themselves in highway traffic, available within the next few years. Available models already tend to have semi-autonomous features such as automatic emergency braking, blind spot monitoring, adaptive cruise control, and self-parking systems.

Twenty-eight percent of all respondents in the latest AAA survey said they would trust a self-driving vehicle. Nine percent said they weren't sure how they felt about this type of technology.

Younger drivers were less afraid of autonomous vehicles than older generations. Only 49 percent of Millennials, defined as ages 18 to 36, said they would be afraid to ride in a self-driving vehicle. Seventy percent of Generation X respondents (ages 37 to 52) and 68 percent of Baby Boomer respondents (ages 53 to 71) said they would be scared by this experience.

Each generation showed more trust in self-driving vehicles than in the 2017 survey. At that point, 73 percent of Millennials, 75 percent of Generation X, and 85 percent of Baby Boomers said they were scared by the idea of riding in a self-driving vehicle.

Men were also less likely to be afraid of the idea of getting a ride from a fully autonomous vehicle, with just over half—52 percent—saying they were unnerved by this experience. By comparison, 73 percent of women said they would be afraid to ride in a self-driving vehicle.

Although respondents reported more comfort with self-driving vehicles than a year ago, most remained wary of sharing the road with an autonomous vehicle. Forty-six percent said they would feel less safe with a self-driving vehicle on the same road as them, while only 13 percent said they would feel more safe. Thirty-seven percent said they would be indifferent in this situation, and 4 percent were unsure.

Millennials and men were again the least likely to be concerned with self-driving vehicles in this area, with 34 percent of the former group and 36 percent of the latter group saying they would feel less safe sharing the road with an autonomous vehicle. This concern was shared by 47 percent of Generation X, 54 percent of Baby Boomers, and 55 percent of women questioned in the survey.

Respondents were also less likely to say they wanted semi-autonomous technology in their next vehicle, with 51 percent saying they would be in favor of these features – down from 59 percent in the 2017 survey. Twenty-seven percent of respondents said they wouldn't want this technology, and 23 percent were unsure.

AAA noted that while more than nine in 10 crashes are the result of human error, most drivers considered themselves to be safe. Nearly three-quarters of the survey's respondents—73 percent—said they considered themselves safer than other drivers. Eighty-eight percent said they held this opinion because they thought they were more cautious than others, while 84 percent said they obeyed traffic laws and 81 percent said they avoided distractions behind the wheel.

"AAA found that American drivers are very confident in their driving abilities, which may explain some hesitation to give up full control to a self-driving vehicle," said Brannon. "Education, exposure, and experience will likely help ease consumer fears as we steer toward a more automated future."

The survey was conducted between December 7 and 10 and polled 1,004 people.