Formula 1 uses state of the art circuits that allow drivers to push their cars to the limits. While every circuit is unique, there is one common theme between all of them – kerbs (or curbs). Since you see them at every circuit, you might be wondering why F1 tracks have kerbs.
F1 tracks have kerbs to mark the track limits. Kerbs allow the drivers to drift slightly off the track without being as heavily punished by the runoff area as they would with grass or gravel. Drivers sometimes use kerbs to their advantage by shortening the corner or running wider at the exit.
Kerbs are a common theme on all racetracks, not just in Formula 1. Even when the drivers are in karting, they’re already learning how to use kerbs to their advantage. But there are some instances where drivers will be avoiding kerbs at all costs. Read on to find out more about kerbs in Formula 1.
What Are Kerbs/Curbs In F1?
Kerbs or curbs in F1 are the (normally) red and white strips at the edge of the circuit most commonly found in corners. They are used to mark the track boundaries, and they come in different shapes and sizes. They’ll usually be found on both the inside and the outside of the track.
Some circuits have different colors of kerbs. For example, the Interlagos circuit in Brazil has white, green, and yellow kerbs, so they’re not strictly red and white. However, they all generally serve the same purpose.
Kerbs are used to mark the edge of the circuit through corners, and drivers are allowed to go over these kerbs as long as part of at least one of their tires is still touching the white line separating the track and the kerbs. If they don’t adhere to this rule, they’re said to be breaching track limits.
Other Runoff Solutions
Aside from kerbs, there are several other runoff solutions that circuits can use. Oftentimes these runoffs are found behind the kerbs, but sometimes there are no kerbs separating the track from the runoff areas, making it much trickier for drivers to navigate around the track limits. This is usually the case on straights or parts of the corner that are not usually near the racing line.
Some circuits use grass runoffs, which is common at many older circuits. Grass is a cheap and easy runoff area, but it does not offer much resistance for the car in terms of slowing them down. Grass also offers very little grip, especially in the wet, as we saw at Imola in 2021 when George Russell dipped his tire onto the wet grass trying to overtake Valtteri Bottas, before spinning both cars out.
Gravel is another popular runoff solution that is used in Formula 1. Many people in the Formula 1 community have been calling for more gravel traps to be used without kerbs in order to enforce track limits. Gravel is far more disruptive if a driver runs wide onto it, often making the driver lose control, and it’s also very difficult to get out of if you lose too much speed.
Gravel is also preferred by many as it slows the car down better than grass or tarmac can. This is because the cars dig in to the gravel, losing momentum quickly. We saw this happen at the 2022 Formula 3 race in Belgium, when two cars collided at the Blanchimont corner, which had just recently had gravel traps added. It’s likely this gravel made the crash less severe than it could have been.
What Are F1 Kerbs Made Of?
F1 kerbs are made of different materials depending on the type of kerb it is. The most common types of kerbs that you’ll see are the raised kerbs, which are made of metal. The metal kerbs can be designed in varying angles and heights, creating different scenarios for each corner.
The metal kerbs can be given a smaller angle and a lower height for faster corners, and a higher height and angle for slower corners. These kerbs are bolted into the ground and cars can easily drive over them. These kerbs can also be moved from time to time. In some instances, the race organizers might move the kerbs slightly depending on feedback from Formula 1 and the drivers.
Some kerbs are simply painted onto the track and mark the track limits, but the drivers do not feel these kerbs when they are in the car. Rumble strips are another type of kerb commonly found in F1, and these are sometimes carved into the tarmac before being painted, and other times they are raised off the circuit.
KEY POINTS
• Kerbs are used in F1 to denote the edges of the track
• Drivers often go over them, but they may be penalized if they go too far over them
• Kerbs are made of different materials, with metal being a common choice
Why Do F1 Tracks Have Kerbs?
Kerbs are used at every circuit on the Formula 1 calendar, even street circuits that are normally used for road cars throughout the year. Kerbs serve an important purpose around a Formula 1 track though, which is why you’ll see them everywhere.
While the type of kerbs and the colors that they are painted might vary from circuit to circuit and corner to corner, they all serve much the same purpose. Kerbs in Formula 1 can most often be found where there are corners on a circuit.
Track Limits
Kerbs are mainly used to mark the edges of the track. Technically, the track limits are defined by the white line on the outer edge of the track, between the tarmac and the kerb (or runoff area at parts of the track where there are no kerbs). The kerbs are used to keep drivers within these limits as much as possible.
However, the cars can still run over the kerbs, which means that they do not necessarily stop the cars from exceeding track limits, but instead they warn the drivers that they are close to the edge of the circuit. Since the kerbs mark the outer edges of the track, they’re a great way to keep the drivers within track limits.
Since kerbs are raised off the track, drivers will feel their cars lifting up as they go over them. Rumble strips may be used, which send a vibration through the entire car that the driver can hear and feel, much like the rumble strips on the highway that keep drivers alert in their road cars.
Safety
Kerbs are also used as a safety element in Formula 1 to some degree. Some kerbs force the drivers to reduce their cornering speeds, which prevents them from attacking the kerbs too aggressively and potentially losing control of the car.
Some kerbs, such as the ones in Monaco, are designed to prevent a driver from getting too close to the barriers. However, if a driver is too aggressive on these kerbs, they could easily be sent into the barriers because the kerbs don’t offer as much grip as the tarmac. There’s a fine line between attacking a kerb to gain time and taking too much kerb and losing control of the car.
On other circuits, such as Monza, the kerbs separate the tarmac on the track from gravel traps. Going too wide on the exit of a corner and running over a kerb can cause the car to dip a wheel in the gravel and get caught up, often resulting in the car spinning off the track.
Why Are Kerbs Mostly On Corners?
You may have noticed that kerbs are most often found around corners on Formula 1 circuits. While there can be some kerbs along straights, they’re more likely to be seen in the corners. Kerbs are simply not put along straights because the cars do not usually exceed the track limits there.
In the corners, drivers get right up to the edge of the circuit to make the corner radius wider, allowing them to go through the corner faster than if they stayed only on the tarmac. Having kerbs on the outside of the track warns them that any further and they’ll likely end up in the gravel or other runoff that sits on the other side of the kerb, or simply exceeding track limits.
The kerb on the inside of the corner prevents drivers from cutting the corners. If they do cut the corner, their cars tend to bounce over the kerbs, which is not only slower but can also damage their car.
Why Do F1 Drivers Use The Kerbs?
Formula 1 drivers always use the kerbs on circuits. Every driver is unique in their driving style, which means that they often use kerbs to varying degrees. Some drivers use kerbs more aggressively, whereas others will use them more passively and try to avoid bouncing the car over the kerbs.
There isn’t necessarily a right or wrong way to use the kerbs in Formula 1, and it all depends on what the driver is most comfortable with and how they navigate their car around the corners. However, drivers can be too aggressive on the kerbs causing their car to pick up some damage, from the wings to the floor and even the bodywork.
Using the kerbs is not always a good option. Formula 1 cars have extremely low ride heights, which means that they can become unsettled if they are lifted too high off the ground. High angle kerbs should be avoided or attacked in a more passive style.
Taking Too Much Kerb
Taking too much kerb is when the driver uses the kerbs too aggressively or puts too much of their car onto the kerbs. This can result in the driver losing control of their car because of the fact that their car lifts into the air. It could also end up damaging the car if they take too much of a kerb that is too high for the car to take safely.
Taking too little kerb is not something we often hear in Formula 1, but it can happen. Drivers take too little kerb when they don’t put enough of their car over the kerb. This will cause them to lose time in their lap by not making full use of the track limits in a corner. The less kerb a driver takes, the more they need to turn through the corner, which slows them down.
Ultimately, drivers aim to make their corners as “straight” as possible. This means that drivers try to turn their steering wheel as little as possible. The less they need to turn their steering wheel, the faster they can get around the track. The best way to “straighten” a corner is to take more kerb at the apex and run wide on the exit of the corner.
Using Kerbs On Corner Entry
Kerbs are placed on the inside and outside of the corners. Drivers will usually hit the apex of the corner when their front tire is on the kerb. Drivers will try to get their car as close to the inside kerbs as possible, usually running slightly over them. This is often referred to as “attacking the kerbs” in Formula 1.
The amount of kerb that a driver takes refers to how much of their car they have over the kerb. There are a lot of different factors to consider in a driver’s decision on how much kerb to take, and a driver needs to manage their kerb usage in Formula 1.
Drivers are much more aggressive on kerbs during qualifying. Taking more kerb is often advantageous because it allows the driver to “cut the corner” ever so slightly. Going over a kerb is always faster than going around it, but it’s important to judge the kerbs correctly. Take too much kerb and the driver could spin or damage the car. Take too little kerb and the driver will be slower.
Using Kerbs On Corner Exit
There are also kerbs on the exits of corners at the outer edge of the circuit to mark the track limits. There are policed much more strictly by the FIA throughout race weekends, especially on circuits where the kerbs are fairly low and easy to drive over. Track limits have caused massive debate in the Formula 1 community over the years
The Formula 1 rule book states that the circuit is defined by the white lines. Any driver that crosses the white lines with all four tires will be exceeding the track limits, which will result in their lap time being deleted. Drivers will also be given warnings for running too wide on the exits of corners during a race, and multiple infringements will result in a black and white flag.
Drivers will always try to run as wide as possible and use the exit kerbs as it allows them to widen the radius of the corners. Running wide on the exit allows the drivers to unwind their steering wheel earlier in the corner and accelerate earlier through the corner, giving them a significant speed advantage.
When Kerbs Are Risky
But the drivers won’t always be able to use as much of the kerbs as they’d like. When it starts to rain, kerbs can become incredibly slippery and cause the cars to spin. Depending on the amount of water on the track and the type of kerbs, a car can be sent into a spin as soon as the tires touch the kerb in wet weather conditions. You’ll still see them use some kerbs though.
Drivers can’t attack kerbs too aggressively when it starts to rain because it increases the chances of the car aquaplaning. Aquaplaning happens when the car’s wheels are lifted off the circuit and lose grip due to water separating the rubber from the tarmac, which sends the car into a spin that is extremely difficult to recover from.
KEY POINTS
• F1 tracks have kerbs to warn the drivers when they’re at the edge of the track
• These kerbs come in many different forms, but they’re usually found in the corners
• Drivers will use the kerbs to make the corners easier to take at higher speeds
F1 Kerbs And Track Limits
The track limits debate has always been a controversial one in Formula 1. In 2022 specifically, there was a lot of debate over the fact that there are different race directors at each Grand Prix, which leads to inconsistent monitoring of the track limits. This has left some drivers frustrated as they need to adjust their application of the rules from race to race.
Officially, the track limits are considered to be the white lines on the edge of the circuit. This means that the kerbs on the outer edges of the circuit are technically a gray area that the drivers can use to an extent. Drivers aren’t allowed to have all four wheels over the white line and onto the kerb, or else they will have their lap time deleted.
Lack Of Consistency
To make it even more confusing, track limits are not enforced in this way at every single corner or at every circuit. At every race weekend, the race director will decide which corners will give the drivers an advantage if they were to exceed the track limits, such as the final corner at the Red Bull Ring in Austria. In some corners, there just isn’t much to gain by exceeding track limits.
The argument against enforcing track limits is that every driver will be able to take advantage of running wide at a specific corner, which means that no one will gain an advantage. This would also remove the confusion of which corners have track limits enforced. Ultimately, the FIA must ensure that they are consistent in enforcing track limits across all circuits.
Types Of Kerbs In F1
There are several different types of kerbs in Formula 1. Each circuit makes use of different kerbs depending on the types of corners that are found on the circuit. Other factors that influence the types of kerbs on a circuit could be the elevation changes in the circuit and the types of runoff areas that are used.
The most common kerbs are metal kerbs that can vary in size and angle. These are bolted into the ground on the edge of the circuit. Drivers can attack these kerbs with ease, especially if they don’t have large angles and stand up too high above the tarmac.
Rumble strips are also often used on the exits of corners. Rumble strips do not slow the cars down, but they will let the driver know that part of their car is off the circuit. Sometimes rumble strips can send vibrations through a car that cause further damage to a car that has suffered some contact throughout a race, so drivers may be instructed by their race engineers to avoid these kerbs.
Sausage Kerbs In F1
Sausage kerbs are some of the most controversial kerbs that have been used in Formula 1. These aggressive kerbs stick out above the circuit, and they are used to prevent cars from cutting corners or exceeding track limits. However, due to their height, the cars can’t glide over them with ease.
Single seater cars such as the ones in Formula 1 are low to the ground, and sausage kerbs are far too high for them to be driven over at speed. Following several massive crashes caused by sausage kerbs, Formula 1 drivers have urged the FIA to remove these kerbs from the circuits when single seater cars race there.
Sausage kerbs have been the cause of some massive shunts in junior single seater series too, including those of Sophia Flörsch at Macau in 2018, Alex Peroni at Monza in 2019, and even more recently at the 2022 Silverstone Formula 2 race, when Dennis Hauger was launched into Roy Nissany’s car.
KEY POINTS
• While kerbs are used to denote the boundaries of the track, controversy still exists about the policing of track limits
• Kerbs come in many different forms depending on the nature of the circuit
• Sausage kerbs are the most controversial type of kerb in F1
Final Thoughts
Kerbs in F1 are used to mark the edges of the circuit, often signaling the track limits that drivers are not allowed to exceed. Drivers will attack kerbs as much as possible to take corners faster and reduce their lap times. There are many different types of kerbs used in Formula 1.
I created and have been writing on this site since 2019, collaborating with drivers, coaches, engineers and manufacturers to provide you with the most reliable information about motorsport. Find out more about me here.