The latest version of Tesla's automatic lane-changing feature may actually be less safe than a human driver, according to Consumer Reports.

An April update to Tesla's autopilot software allows automatic lane changes on certain roads as part of what the company dubbed a more "seamless" experience. The feature works so long as Tesla's autopilot system is activated and drivers have plugged in a final destination. The function also can be turned off.

But when Consumer Reports tested the feature, reviewers came back with concerns it could create potential safety risks. Consumer Reports found that cars in autopilot mode often cut off other vehicles or broke laws while trying to pass. Its verdict: The lane-change function "raises serious safety concerns."

In fact, "Tesla is showing what not to do on the path toward self-driving cars" by launching automated driving features "that aren't vetted properly," said David Friedman, vice president of advocacy at Consumer Reports, a nonprofit that tests products and conducts consumer-oriented research.

"Before selling these systems, automakers should be required to give the public validated evidence of that system's safety — backed by rigorous simulations, track testing, and the use of safety drivers in real-world conditions," Friedman said.

At least three fatal crashes in the U.S. have involved Tesla's driver-assistance features. Most recently, a Model 3 collided with a tractor-trailer. According to a preliminary report from the National Transportation Safety Board, the driver had turned on autopilot about 10 seconds before the March 1 crash. The driver was killed.

The crashes have heightened questions around the safety of the technology and to what extent drivers can or should rely on it. Still, Chief Executive Elon Musk is setting lofty goals for even more self-driving features. He has said that autonomous Tesla taxis will shuttle passengers by the end of the year.

In a statement to Consumer Reports, Tesla said that, "Navigate on Autopilot is based on map data, fleet data, and data from the vehicle's sensors. However, it is the driver's responsibility to remain in control of the car at all times, including safely executing lane changes."

In an April 3 blog post, Tesla said that it regularly examines data from when drivers took over the lane change feature, and that drivers like the option for daily commutes.

Consumer Reports' testers also disputed Tesla's pitch that the car's three rear-facing cameras can spot a fast-approaching vehicle faster than the average driver.

The testers also had to cancel lane-changes that had been approved by autopilot because they felt it wouldn't be safe. In other words, the driver often intervened to prevent the system from causing harm, Consumer Reports said.