Blind spots could be a thing of the past, if only replacing car mirrors with the latest technology was legal.
Last week at the Consumer Electronics Show in Las Vegas BMW showed off a prototype vehicle where the rear- and side-view mirrors were replaced by cameras, which the carmaker says give drivers a more complete picture of what's happening behind them.
Video footage from three cameras, one on the rear windshield and two replacing the traditional side mirrors, is pieced together on to a broad video screen that replaces the traditional rear-view mirror.
It's the latest example of carmakers' interest in reinventing the mirrors in vehicles to provide better visibility for drivers and a more aerodynamic, fuel-efficient design.
Experiments with new formats of mirrors are nothing new. In 1969 researchers working on behalf of the federal government outfitted a Chevrolet Impala convertible with a six-foot (1.8m) wide mirror that gave drivers an unobstructed rear view. It worked on the convertible because there are no rear beams to block the driver's rear sight lines. But it was never taken seriously by carmakers because of huge styling and aerodynamic issues.
But things are a little different now.
"There's no longer a strong barrier of technology or price," said Michael Flannagan, a research associate professor at the University of Michigan's Transportation Research Institute, of replacing mirrors with cameras. "The fact that so many back-up cameras are in use has made the technology for vehicles mature very rapidly. It has set the stage for an even greater use."
Flannagan said the most promising opportunity to improve safety is similar to what BMW is doing, in which drivers are given a unified field of view. They would no longer have to turn their heads to the left or right to look at outside mirrors.
"The key safety thing is eyes should be directly in front of you, straight ahead almost all the time. The more you can do that the better," Flannagan said.
But no research has been conducted yet showing that camera systems are safer than traditional mirrors.
"There is no research because it's not been allowed up till now," said David Zuby, the chief research officer at the Insurance Institute for Highway Safety. "Conceivably an array of cameras could give you a broader view of what's going on around the car than a side-view mirror." He also cautioned that the camera lenses for such a system would have to be kept clean to be effective. And the electronics would need to be proven as durable and long-lasting.
With a camera-based system some drivers also would no longer have the potential problem of struggling to pivot in their seat to check their blind spots.
BMW has not released a timeline for when it expects the mirrors could be included on its vehicles.
That in part is because US government guidelines still call for mirrors. These rules were developed before cameras emerged as a viable alternative.
Last spring the Alliance of Automobile Manufacturers and Tesla petitioned the federal government to update its standard for rearview mirrors to allow camera-based systems. They're still waiting.
The earliest photos Tesla released last summer of its new Model X SUV didn't include side-view mirrors, but small cameras replacing them. However when Tesla officially unveiled the actual vehicle, it still had the traditional mirrors, in accordance with government rules.
While acknowledging the safety and design benefits of switching to camera situations, Luke Neurauter, who conducts advanced automotive research at Virginia Tech's Transportation Institute , cautioned that research needs to be done to make sure the implementation of camera systems doesn't confuse drivers who are used to traditional mirrors.
"Ideally it's something any driver can hop in and intuitively use and understand," Neurauter said. "Yes you're seeing more with cameras but are you accurately judging the distance of the car and the approaching speed to make a safe lane-change judgment?"
But to offer such a solution on a typical car or truck will rely on switching to cameras, and government clearance. A Department of Transportation spokesman said that the agency is looking for ways to accelerate innovations that can improve safety, and is reviewing its standards to see if anything is hindering such developments.