When was the first rear-view mirror used in a vehicle?

‘Mirror, signal, manoeuvre’ is the simple mantra that every learner driver has drummed into them when they start taking lessons. For this very reason, we take the small glass rectangle mounted to the headliner for granted, and may have never questioned what the genesis of this idea was.

The idea of the rear-view mirror originated in motorsport, and we have engineer and part-time racing driver Ray Harroun to thank for it. When Harroun was competing, it was standard practice to have a mechanic accompanying the driver. As well as fixing any problems, it was their job to act as lookout and warn the driver of other cars closing up on them.

Harroun designed his Marmon Wasp racer – so named because of his employer and because of its distinctive black and yellow colour scheme – as a lighter, more streamlined single-seater. Compared with the side-by-side, driver-mechanic layout, this meant a smaller frontal area which, combined with the long, teardrop tail, significantly reduced aerodynamic drag.

This gave Harroun a competitive edge, but to give him the situational awareness needed to win races, he developed a rear-view mirror – one inspired by a feature he’d seen used on horse-drawn carriages in Chicago some years before. It was housed in a metal casing attached by four slender struts to the cockpit cowl, just above his line of sight.

On 30 May 1911, Harroun’s innovation helped his six-cylinder racer win the inaugural Indianapolis 500, after lapping the brick-surfaced track for 6 hours, 42 minutes, and 8 seconds.

It wasn’t long before rear-view mirrors were adopted by the growing number of passenger car manufacturers worldwide, and these simple yet effective devices began to make their contribution to vehicle safety by making drivers more aware of the traffic around them.

Another breakthrough came half a century after Harroun’s Indy 500 win: In 1961, Jacob Rainbow was granted a patent for a ‘Photoelectrically controlled rear mirror’. To save drivers from having to manually operate a lever to change the angle of the mirror to reduce dazzle from the headlights of cars behind them, Rainbow’s invention used a combination of photocells and electromagnetic actuators to do the job for them.

The next advances came with digital technology, and the invention first of photochromatic mirrors, and then the addition of data such as compass bearings, then video feeds from reversing cameras.?

The state of the art now includes rear view mirrors that can toggle between a normal view, or a complete, wide-angle display of the road behind, enabling the driver to see what might otherwise be obscured by rear-seat occupants or objects in the luggage compartment.?

Digital "rear-view mirrors" enable innovative designs and aesthetic approaches, such as those seen in the Polestar 4—an electric performance SUV coupé. This vehicle features driver assistance technologies integrated by ECARX and Mobileye , which replaces the rear window with sheet metal extending to the roof.

Looking further into the future, rear view mirrors could take another leap forward and use augmented reality to enhance the information shown to the driver – or, in a fully autonomous vehicle, the mirror may become redundant altogether.

Technologies such as the ECARX Makalu fifth-generation, ultra-high performance digital cockpit platform has the computing power necessary to power innovations like these, delivering incredible real-time, 3D rendering capability and ultimately making journeys safer and more enjoyable for all vehicle occupants.