Four out of 10 Americans overestimate the capabilities of semi-automated driving systems based on their names, which indicates a lack of understanding of the technologies and a possible safety risk, according to a new survey from AAA.

Specifically, the survey found that names like Autopilot, ProPilot or Pilot Assist led many people to believe the system was entirely autonomous and had the ability to drive the car by itself.

Millennials were the top group to be misled by the system names, with 59% believing the system could drive the vehicle. Generation Xers ranked second, with 40% sharing that view. However, only 27% of Baby Boomers were fooled by the system names.

To assess the actual capabilities of partially automated vehicle systems, AAA also tested the systems to see how they performed in common driving circumstances. Testing was done on both a closed course and on public highways using four test vehicles equipped with the technologies.

The findings indicate that today's partially automated driving systems are not designed to take over the task of driving and can be significantly challenged by common, real-world conditions like poor lane markings, unusual traffic patterns and stationary vehicles.  

One key finding included that 88% of events that called for driver intervention in a real-world setting were due to the vehicle's inability to maintain lane position.

The challenging lane-keeping events occurred most often on freeways with moderate traffic and by urban driving along surface streets. Systems generally performed best on open freeways and freeways with stop and go traffic.

Closed-course testing revealed another key finding that three of four test vehicles required driver intervention to avoid colliding with a simulated stationary object.