What is the red light at the rear of F1 cars?

Jake Nichol December 3, 2021
What is the red light at the rear of F1 cars?
Photo by Xavier Bonilla/NurPhoto via Getty Images


You might have noticed a red blinking light at the rear of F1 cars when they are out on track, but what does it mean? What information does it tell other drivers?

It’s a common thought, but Formula One cars do not have brake lights.

Drivers generally hit the brakes in the same place when approaching a corner every lap, so don’t need to know when the car in front has thrown the anchors out.

But whilst they do not have brake lights, Driver H can sometimes come across a rival, say Driver V, going slower than expected on a straight.

It is here the red lights at the rear of Driver V’s car will be blinking,

But what information does this convey to Driver H?

And what is the primary use of the red light at the rear of F1 cars?

Photo by Darren Heath/Getty Images

F1 car red lights explained

First and foremost, the red light is used as a safety tool in heavy rain conditions.

In such weather, cars throw up heavy spray – water displaced by the tyres.

This decreases visibility and makes it hard to see the car in front.

Photo by JOHN THYS/AFP via Getty Images

Drivers in the midfield and towards the rear sometimes say over team radio that they can’t see anything due to the spray in the rain.

This is why the red light was first introduced into F1.

It is a safety device to allow drivers to know where others are when visibility is low.

A new function in F1

This was the red light’s only function until the advent of the turbo hybrid engine formula in 2014.

However, after the simple V8 engines were consigned to the history books and energy harvesting and deployment became a thing, the red lights took on a new function.

Owing to the need for cars to need to charge their energy batteries from time to time when on-track, the red lights were re-purposed.

F1 2021 | October Free Content Updates Trailer

F1 2021 | October Free Content Updates Trailer

It now blinks when the car is de-rating, or charging its batteries.

If Driver H is behind Driver V, it warns the former that the latter could be slower on a straight as they are charging their energy pack.

It was a blinking red light which helped cause the famous collision between Lewis Hamilton and Nico Rosberg in 2016.

Rosberg switched his Mercedes into a charging state on the opening lap, with Hamilton diving to the inside as the sister Merc was slower off Turn 3.

At Turn 4, the two collected each other and ended up in the Spanish kitty litter.

The entire red light system received an upgrade in 2019.

To increase visibility, additional lights were added in the rear wing supports to form a triangle of blinking red lights.

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Photo by Clive Mason/Getty Images

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Jake can usually be found writing about or watching anything to do with motorsport – from Formula 1 to NASCAR to British Truck Racing. His work as a motorsport journalist has been published by the likes of Autosport, Motorsport.com and Motorsport News – all highly respected names. Away from racing he is a keen amateur astronomer, podcast listener and enjoys long walks in the park with his three dogs.