Self-driving cars will roam the streets in large numbers by 2021, but a recent Kelley Blue Book poll shows that self-driving enthusiasm might be a little too accelerated.

A whopping 62 percent of the surveyed do not expect to see all vehicles featuring autonomous tech in during their lifetime. What is truly surprising is that 30 percent of the 12 to 15 demographic agree with the opinion of the majority.

Meanwhile, auto builders and tech companies such as Ford, Google and Uber are touting that 2021 will be a grand debut year for self-driving cars.

Karl Brauer, a senior analyst with Kelley Blue Book, explains that for the large public, autonomous vehicles are "still like a flying car, something out of The Jetsons."

"We learned that it's hard to get people on board, but any level of exposure changes perceptions quickly," Brauer points out.

Kelley Blue Book talked to 2,264 people ages 12 to 64, a part of which are not drivers.

The survey also included a number of car owners who saw some degree of self-driving features, such as the Mercedes E-Class and the Tesla Model S. Not surprisingly, 94 percent of that group confirmed that they feel safe thanks to the technology present in self-driving cars.

Only 39 percent of those whose cars did not have any self-driving options said they feel safe in such a vehicle.

Advocates of autonomous driving reason that ceding control to on-board systems would curb the national figure of 35,000 deaths per annum, most of which can be linked to human error. Google's self-driving cars were involved in a few accidents, but the majority of them happened due to other drivers mistakes, including a recent one where the culprit ran a red light.

On the other hand, skeptics argue that the tech raises questions regarding regulation, privacy and safety.

Brauer believes that the hardest pill to swallow is the idea that drivers will lack any control of the vehicle, as Level 5 autonomy will be reached. As a reminder, Level 5 autonomy implies that no human control is required for the self-driving car to operate. Both Ford and Google affirm loud and clear that they want to put level 5 ride-hailing cars on the streets by 2021, which will feature no pedals or steering wheels.

Read on for more interesting findings in the poll.

56 percent of respondents prefer to get picked up in an Uber or Lyft that has a human at the wheel vs a computer. 69 percent of ride-sharing services users would feel safe in a Level 5 car, while only 42 percent of non-ride sharing respondents would not. A strong 80 percent of those surveyed said that "people should always have an option to drive themselves."

79 percent are aware of the existence of "self-driving vehicles," while only 41 percent know what an "autonomous vehicle" is.

If we spiked your interest, you can download and read [PDF] the full result of the survey.