As you may know, I'm weirdly obsessed with vehicle lighting systems. It's unhealthy. My wife has made me leave my collection of marker lights in the closet when we're, um, intimate. But still, I feel there's things I need to address. Like cornering lights.
Cornering lights are one of those types of vehicular lighting that aren't required by law anywhere, and aren't even particularly common. They're entirely voluntary, simply a good idea that gets implemented by thoughtful car-makers every now and then.
They're pretty much what the name suggests: a light used to help when turning corners. They're not so much an indicator light to communicate an intent to other drivers, but more of a light to help with visibility for the driver themselves. In that sense, they're more like headlights, or perhaps reverse lights.
Cornering lights are normally white lights positioned usually at the front fenders of the car — very occasionally at the rear as well — and often integrated with the front side marker and/or turn indictaor lights. When the turn signal is activated, they illuminate, casting light around the corner being turned, so the driver can see the curb, the road, or the packs of ice weasels that may be lurking right around a dark bend.
Corner lights were introduced by Cadillac in 1962, and soon spread all over the GM fleet. As the delightfully obsessive site AutoBrevity says of the lights:
In 1962, Cadillac announced a few new safety features, including the first separate front and rear braking systems. Among the new safety features for the year was an item Cadillac called the cornering lamp. Marketed by Cadillac as a safety feature, the brochure presented it as "...an exclusive new cornering lamp that lights your way around turns..." And it was part of the standard equipment package on every Cadillac model for 1962.
The cornering lamp was mounted near the forward edge of the front fender, just above the wrap around part of the bumper. It consisted of a clear lens surrounded by a chrome bezel, and it projected a clear, bright, steady beam of light in the direction of a turn. Operation of the cornering lamp was controlled by the turn indicator switch, which turned on the corresponding cornering lamp automatically, and the light was extinguished when the turn indicator was cancelled by returning the steering wheel back to the straight ahead position. The cornering lamp was wired through the headlight switch so it only worked when the parking or headlamps were turned on, as Cadillac felt it would be most effective during the hours of darkness or inclement weather.
The steady beam of bright light helped illuminate the way around dark corners, a benefit especially appreciated by drivers navigating their way in unknown territory. The cornering lamps also served as a warning to oncoming traffic that a car was about to make a turn. They were also helpful in illuminating addresses stenciled onto curbs, and they became part of the Twilight Sentinel feature, which not only automatically turned on and off headlamps according to lighting conditions, but allowed drivers to leave the headlamps on upon exiting the car to illuminate their way into their homes. One of the cornering lamps could also be illuminated by moving the turn indicator in the direction of the desired light. The delay period could be set from several seconds to several minutes, depending on individual preference.
This feature would become a staple of Cadillac's standard equipment from that point forward, and is still found on the new models. There are a few exceptions, such as the Cadillac Cimarron, which many Cadillac enthusiasts don't consider a true Cadillac anyway, but the vast majority of Cadillacs built since 1962 all have this one thing in common.
The case of the C4 Corvette is especially interesting. Cornering lights were normally a staple of big American sedans and luxury cars, so having them on a sports car like the 'Vette was already unsual, let alone having them at the rear as well. Really, if your main criteria for buying a car was safe, well-illuminated cornering, you really can't do better than a C4 Corvette.
Cornering lights showed up on many American cars (Ford LTDs, for example) and a few foreign makes as well — the always safety-concerned Swedes stuck them on many Volvos and Saabs.
They're still around on a number of cars, and steerable headlights have replaced them on some makes, but there's still a lot of appeal to these often-unsung little illuminators of the dark bends.
I encourage everyone to look around for some cars with cornering lights as you drive around tonight, or, better, if your car has them, really revel in those crisp white beams shooting out of your sides.