If you've watched a Formula 1 race before, you've probably noticed the presence of the red light on the back of the cars before. You might be wondering what exactly this light is for, since if you pay attention, you'll see that the light is often flashing in situations where the car isn't braking.
Having been a required feature on all Formula 1 cars since the 1970s, this light is indeed used for safety, although its purpose might not be what you'd expect (and its purposes have changed a bit since it was first implemented). In this article, we'll be talking all about this mysterious red light and what it's actually used for.
If you've only managed to get a quick look at the light on the back of a Formula 1 car, you might have assumed that the light was just a brake light. This is not so; while the light is a safety feature, it's not used to indicate when the car is braking.
In fact, Formula 1 cars don't even have brake lights at all. While you might at first think this to be an incredibly negligent safety oversight on behalf of the car designers, this is decidedly not the case. The truth is that on a Formula 1 car, brake lights would be kind of a redundant feature.
On a public road, you have people braking at different times depending on the obstacles/intersections they're slowing down for, so it makes sense to have a way to let other drivers know when they might be slowing down. During a Formula 1 race, on the other hand, all of the drivers are going to slow down at pretty much the same spots throughout the circuit.
There's also the fact that even if Formula 1 cars did have brake lights, the cars are travelling so fast that if a driver were to brake unexpectedly they would probably still get rear-ended regardless. Of course, it's very rare that a driver has to apply the brakes unexpectedly during a race anyway, which makes brake lights even less necessary.
So, if the red light on the back of a Formula 1 car isn't a brake light, then what is it for? As we've mentioned, the light is indeed used for safety, but it indicates things other than braking.
This light can actually serve two different purposes, depending on the situation. The first situation where you'll see the light being used is during rainy weather when visibility is especially low, to prevent drivers from crashing into each other.
Since Formula 1 cars don't have windshields/windshield wipers or even a way to quickly wipe off the visor on the drivers' helmets, it can get pretty hard to see when the rain really starts coming down. This is also not helped by the fact that cars kick up a big spray of water behind them when travelling over wet pavement.
Aside from the flashing light near the bottom of the car, you'll also notice that Formula 1 cars have two additional lights on either side of the rear wing that turn on when it's raining. These three lights are the only lights you'll find on the exterior of a Formula 1 car.
The second purpose of the flashing red light is actually to serve as a warning for when the car is going a bit slower than normal, but not because of braking. Modern Formula 1 cars have what's called an Energy Recovery System (ERS), which harvests unused kinetic and thermal energy and converts it into extra power the car can use later.
When the ERS is running, however, it causes the car to be a little bit slower than normal. Thus, the flashing red light at the back of the car serves to warn other drivers that the ERS is active.
On very rare occasions, you might have seen a Formula 1 car displaying a green light on the back instead of a red one. If you see this, it means that the car is being driven by a rookie driver who doesn't have their full FIA Super License yet.
To race in Formula 1, you need to have an FIA Super License, which is a qualification proving that a driver has the knowledge and experience to compete in Formula 1 on a professional level. Occasionally, however, you have a situation where a driver meets all of the qualifications to have a Super License but doesn't actually have the license yet.
In these instances where drivers are technically qualified to compete in Formula 1 but don't officially have the certification to do so, they are allowed to race but must display a green light on their cars. Most recently, drivers Alex Albon and Pietro Fittipaldi have had to display the green light because of this regulation.
How Do Formula 1 Cars Drive in the Rain?
The flashing red light on the back of the car certainly does a little bit to make wet-weather driving during a Grand Prix a little safer. But even if you're in a regular commuter car, it's no secret that driving in very wet conditions is inherently more dangerous. So how do Formula 1 cars maintain high speeds safely in heavy rain?
For one, Formula 1 cars have special tires they can use when it's raining. Unlike the racing slicks that the cars usually use, rain tires have actual treads, which vastly increase their grip on slick surfaces.
Of course, if it's raining too heavily, the race organizers might decide to just cancel the race outright. Visibility is the real hazard when it starts raining heavily, and the spray that the cars kick up behind them doesn't help either. As driver Sergio Perez once described it, "[driving in the rain is] the same if you close your eyes or keep them open. You don't see anything."