Nearly six in 10 Americans believe self-driving vehicles are not as safe as those operated by human drivers, and 55% wouldn't be willing to ride in an autonomous vehicle today, according to a recent survey.

Age matters, when it comes to automated vehicles and safety issues, according to the survey conducted by HNTB Corporation America THINKS. The findings indicate a disparity of opinions among various age groups.

For example, Millennials (ages 18-34) appear to be the most willing to embrace autonomous vehicles, because 54% say self-driving vehicles are safer than those operated by people.

While 60% of Millenials would be willing to ride in an autonomous vehicle today, Gen Xers (ages 35-49) were more cautious. Some 67% of Gen X respondents said the presence of a person who could take control of the wheel, if necessary, would convince them to use the vehicles.

When asked to identify benefits of autonomous cars, Millennials rated improved safety higher than any other group, with 41% of all respondents citing fewer accidents and increased safety as a benefit as compared with 49% of Millennials.

In addition, one-third of Millennials believe the advanced technology will offer improved safety for pedestrians and bicyclists as compared with just 23% of all survey respondents.

HNTB's survey is based on a random poll of 1,010 Americans nationwide, ages 18 and up, between Apr. 27 and 30. It was conducted online by Russell Research.

Read the full survey here.

Related: Drivers Not Ready for Autonomous Vehicles