The 24 hours of Le Mans is one of the most awesome events on the racing calendar. Some of the fastest vehicles in the world will be zipping around the track for 24 hours straight. It is really the ultimate test of endurance. Of course, it would be incredibly unsafe for a driver to be behind the wheel for 24 hours. Eddie Hall managed to complete the entire race alone in the 1950 edition of Le mans 24 and is the only person in history to do so, even though several other drivers have tried in the early years of the event before it was outlawed. Today FIA stipulates minimum and maximum driving times for the 24 hours race. These regulations govern how many drivers can be in a race, and how often they need to switch. Although, they may not be as strict as you may think. Let us have alook at it below
The Number Of Drivers Per Team
Each vehicle in Le Mans can have a maximum of three drivers over the course of the twenty-four hours. Some teams can technically compete with two drivers, as it happened for Bleekemolen and MacNeil in 2014 where their third driver was ruled out due to a medical issue, this is because the rules are relaxed enough in one category to allow that. Although, it is still encouraged to have three drivers willing to take the wheel should something go wrong. In reality it is very risky and difficult to complete the race with only two drivers so teams enter the maximum of three drivers for the race.
Max Driving Time Per Driver
This is where you start to see a bit of a difference between the car classes at Le Mans. In all car classes, no driver is allowed to be behind the wheel for more than 14 hours, hence why you need to have at least two drivers. A single driver would not be able to complete the event. There were as mentioned solo drivers during the early days of Le Mans, but organizers worked out pretty early on that this was just plain dangerous.
In these categories:
Every named driver needs to be driving for at least 6 hours over the course of the 24 hours. The 'punishment' for breaching these rules can vary, and it is up to the stewards to decide what the fair punishment is. In some cases, a team could be excluded from the race. In others, it may just be a distance penalty.
In the LMGTE Pro category, there is no minimum amount of time a driver needs to cover. So, even if three drivers are named, only two ever need to get behind the wheel. It is unlikely that this rule will ever be changed. Remember, the LMGTE Pro drivers are going to be among the best on the track, and they are the people that are built for endurance.
When a driver is swapped out, they will probably head to bed to rest (there are beds for each team), although there isn't any requirement for them to actually sleep once they have been swapped out.
What Are The Le Mans Driver Switch Rules?
This is where the rules start to get a little bit confusing, and they can change 'on the day'.
As we said, drivers are not supposed to drive for more than 14 hours. In all categories, even LMGTE Pro, a driver cannot drive for more than 4 hours every 6 hours. This means that, at a maximum, the drivers will be swapped out every 4 hours, although it doesn't work quite like that (more in the next section).
The rules can change on a hot day, though.
2 hours before the race, the race organizers will share something known as the 'ambient temperature prediction'. In periods where the ambient temperature is expected to be over 32C (about 90F), the drivers have to switch much more frequently. During these times of the race, the driver shave to switch every 80 minutes. There has to be a 30-minute rest period between each swap of the drivers.
For the most part, the ambient temperature prediction times won't change during the race. However, Le Mans teams are expected to monitor the temperature of the insides of their vehicles to ensure that the drivers are competing in safe conditions. It cannot be allowed to get too hot inside the vehicle. This would cause heat stroke, which is insanely dangerous when a person is driving. Just remember how Johnny Herbert missed out on the podium celebrations after winning the 1991 race as he collapsed just after the finishing line (see here).
When Do Teams Switch Their Drivers?
Teams are free to switch their drivers over whenever they want, assuming they are switching in line with all of the other rules that we discussed previously. Of course, since Le Mans is an endurance race, you don't want the drivers to be swapping out continually. The more they swap out, the less distance they can cover.
Most drivers will be driving for between 45 minutes and 4 hours. Remember, in all categories, 4 hours is the maximum amount of time a driver can drive before they need to be switched out. So, it is rare that the team will push a driver all the way to the four hours because they don't want penalties if something goes a bit 'wrong' and the driver is delayed coming back to the pit. You can expect most drivers to drive between 45 minutes and 3 hours before they are swapped out.
The swapping will always happen during a pit stop. During the race cars need to pit every 45-50 minutes to refuel - this is called a stint. When you hear the term stints, double stints or even triple stints this is what they refer to. Tires can usually last around 3 stints, although this varies. Teams often try to switch drivers during the longer pit stops where they are both refuelling and changing tires. This is because a new driver can quickly get into that vehicle long before the tire change has been completed.
Although many factors play into when the teams switch drivers.
Some drivers prefer to drive at night so they get more driving time at night, this usually the stronger driver in a team. The car might have had a mechanical issue that resulted in an unplanned longer pits stop where it made sense for the team to switch driver.
There is also often a gentleman agreement inside the teams that one of the three driver does the main qualifying (i.e. the fastest lap), another starts the race and the third finishes the race. This also needs to be factored into the driver switch frequences. The unfolding of the race can also influence when you want a specific driver in the car.
It will depend on the team's strategy.
Le Mans driver switch rules vary depending on the vehicle that is competing. In most categories, a team needs at least three drivers, and each driver must cover a minimum of 6 hours per race and a maximum of 14. No one driver can cover more than 4 hours in one go. These times can change a little bit on incredibly hot days, which will be incredibly common since the event is held in France in June.