6 reasons why I can't wait for cameras to replace rearview mirrors
As automakers push for more cameras in cars, the tried-and-true three-mirror setup is starting to look a bit archaic.
Pretty soon, you won't be able to buy a car in the US without a camera in it, thanks to the Department of Transportation's mandate for rear-view cameras in all cars built from May 1, 2018. Hot on the heels of that announcement, we heard that Tesla was petitioning regulators to allow side cameras in place of the ubiquitous side wing mirrors. Meanwhile, automakers like Nissan and Land Rover are slapping cameras all over their cars and SUVs, searching for more ways to improve cockpit visibility and driver awareness.
Compared to cameras, the tried and true three mirror setup is starting to look a bit archaic. With that in mind, I've rounded up six advantages that cameras can offer drivers over mirrors and a few challenges that automakers will need to face in order to make the transition.
Better fuel economy
The next time you're cruising in your car, roll the window down and stick your hand out. (Oh and be sure to watch out for oncoming traffic.) The force of the wind that you'll feel pushing on your hand is aerodynamic drag and it's being exerted on your car's wing mirrors across every mile you drive. Sticking out from their homes near the base of the A-pillars, your car's wing mirrors are like little aerodynamic anchors dragging through the air, causing the vehicle's engine to have to work just a little bit harder to maintain a cruising speed.
How much harder? Tesla claims that ditching the wing mirrors could reduce a typical vehicle's aerodynamic drag by 3 to 6 percent. While this doesn't translate directly to a 3 to 6 percent bump in fuel economy (there's still drive-train and road friction and vehicle auxiliary systems to be accounted for), it could mean the difference between your next sedan doing 38 and 40 mpg on the highway, where the aerodynamic gains make greatest difference, or your new EV getting 100 instead of 85 miles of range. Every little bit counts.
(Fun fact: The main reason the Nissan Leaf uses those goofy frog-eyed headlamps is because the designers figured out that a headlamp hump could shape the Leaf's airflow around the wing mirrors, boosting efficiency.)
The same aerodynamic compromise that makes wing mirrors an efficiency liability also contributes to the amount of noise they generate at speed.
As the car punches its way through the atmosphere, air crashes against the wing mirrors creating turbulence, which creates wind noise. Automakers have sunk a good deal of money into making wing mirrors quieter by shaping them aerodynamically, reducing their forward surface area, and adding turbulence reducing strakes, when the simplest solution to a quieter car is just to lop 'em off, replacing them with low profile cameras.
Most people don't know how to properly aim their mirrors to reduce the over-the-shoulder blind spot. (Pro tip: If you can see your door handles, you're doing it wrong.)
Cameras take some of the guesswork out of aiming a mirror because they don't rely on the viewer's relationship to the screen. The camera angle can be set at the factory and not need to be adjusted respective of driver height or fore-to-aft seating position. If you can see the screen, you're golden. To illustrate my point, I've never had to aim a rear camera, but I've to tweak the center mirror at the beginning of every trip.
Cameras can also boast wide-angle optics, offering a much broader field of view than any reasonably flat mirror can and software can overlay guides, such as Honda LaneWatch's distance markers, taking the guesswork out of "objects in mirror are closer than they appear."
Even trickier camera use, such as Nissan/Infiniti's Around View monitor, can provide a more comprehensive view of the area around the vehicle while parking than any combination of windshield and wing mirrors could hope to.
Have you ever glanced in your mirror and been nearly blinded by the glare from some guy's improperly aimed headlamps (or high beams)? Have you ever been waiting a red light, silently swearing at the huge truck or SUV behind you with lights trained at eye level? A camera feed can't ever be brighter than the screen that you're viewing it on, so you can say goodbye to seared retinas with cameras in place of mirrors.
As illustrated by Nissan's Smart Mirror, which is both a mirror and a display for a rear camera, image processing and automatic exposure can reduce the glare of bright light sources and enhance the image quality in low-light situations. Nissan's camera can also help the driver to see around tall back seat passengers, headrests, and bulky cargo filling a hatchback or crossover's rear storage.
Better looking cars
Have you ever noticed that most concept cars don't have huge wing mirrors? Even the ones that do have tiny, impractical little nubs designed to attract as little attention as possible. That's because mirrors are ugly. Trust me, if it weren't for safety regulations, mirrors would have disappeared a long time ago.
Additionally, being able to tuck small, inexpensive cameras more freely around the vehicle's exterior frees up designers to be more creative with design.
Removing the mirrors hanging off of the sides of a car also means that there's one less protrusion to be smacked or snapped off by other drivers or vandals, crushed when backing out of a tight garage, or damaged in automatic car washes. If you've ever returned to your street-parked car to find it short a mirror (and seen how expensive it is to replace or repair) you know exactly what I mean.
A jump to cameras would raise a few considerations that automakers will have to address and challenges that will have to be overcome.
For starters, lenses hate dirt and water. Even though the optics used in an automotive application would doubtless be waterproof, a bit of standing water or dirt on a small lens can seriously obscure vision compared to a mirror's larger surface area. I've seen poorly designed rear cameras get coated by road grime, reducing their effectiveness to nil. On the other hand, I've also seen well designed (and well placed) cameras that shed water quickly and are mounted high where they are protected from the worst road grime. Automakers will need to consider this when placing the cameras that we'll rely on to see around the vehicle.
No doubt many of you are already thinking that cameras will add complexity to vehicle electronics and, of course, to the cost of a repair in the event that they break or are damaged. Automakers will need to work out the kinks and costs here as well, while also addressing the "if it ain't broke" attitude taken by many drivers and regulators toward the simple mirror on a stalk.
Finally, most vehicle dashboard currently only have one or two displays between the center stack and instrument cluster. If cameras are to replace mirrors, they'll need dedicated screen real estate for their always-on feeds. The top-center mirror hanging from your windshield could be repurposed for this, but secondary dashboard displays and windshield head-up displays are also promising plots of visual real estate.
I'm sure that we'll see a few automakers get the display scheme a little wrong before someone gets it very right. Until then, cameras will continue to supplement and work with the very mirrors they'll, perhaps, soon be replacing.