Law enforcement officers are constantly preaching car safety. Making sure drivers and passengers are buckled up before hitting the road. Urging drivers to be aware of speed limits. Issuing repeated warnings about drinking and driving. The list of precautions goes on.

Now we are told by the AAA Foundation for Traffic Safety that most drivers don’t understand the limitations of advanced safety technology installed on new vehicles. Huh? We thought that’s what the driver manual in the glove compartment and the instructions given before driving the vehicle off the lot were for, but apparently that’s not enough.

The AAA Foundation study indicates that drivers overestimate the capabilities of features such as blind-spot monitoring systems, automatic emergency braking and adaptive cruise control.

“A substantial proportion of respondents demonstrated what we believe was a concerning lack of awareness of some of the key limitations of the technologies,” said Brian Tefft, senior researcher for the AAA Foundation. The story on the AAA Foundation study was published in USA TODAY newspaper.

The findings raise questions about whether Americans are ready to adapt to partially self-driving vehicles, which typically require drivers to remain alert and ready to take over the steering wheel if the car can’t handle the conditions it encounters.

Nearly 80% of drivers don’t understand the limitations or thought that the system in blind-spot monitoring had greater capability to direct fast-approaching vehicles, bicycles and pedestrians. Relying too much on monitoring, about 25% don’t look for oncoming vehicles when they change lanes, according to the study.

When it comes to forward-collision warning and automatic emergency braking, many drivers get confused between the two. One is a warning system, while the other takes action, the study noted. More than 40% of drivers don’t know these limitations.

Regarding adaptive cruise control, about 29% of drivers who use the system are sometimes comfortable “engaging in their activities” while the system is activated, according to the study. The system is designed to accelerate and brake on its own.

To be sure, the researchers emphasized that advanced driver assistance systems are generally helpful. Such technologies can prevent about 40% of crashes and 30% of crash deaths, according to federal estimates.

The problem, according to AAA Foundation, is that technology backfires when people don’t understand how it works.

Jake Nelson, director of traffic safety for AAA, said there’s a general assumption among members of the public that technologies in vehicles today will do things for us. “These technologies are not meant to replace us behind the wheel. They’re meant to help us out,” he said.

Nelson said that it’s important for dealers, automakers and rental-car companies to educate drivers at the time they take delivery of their vehicles, on how these systems work.

Traffic safety studies don’t lie. They are meant to teach us how to stress safety when driving. They point out the red flags of the road. Every driver needs to pay attention.