A 24-hour endurance race is as much a human systems problem as a vehicle engineering problem. At Le Mans, each car is shared by a crew of drivers who rotate through stints so the car can keep racing while people recover. Teams plan these rotations around fuel range, tire wear, traffic, weather, daylight, and driver fatigue.
Good stint planning helps maintain lap time, reduce mistakes, and satisfy race regulations.
Key Facts
- Total race time = 24 h = 1440 min.
- Number of stints = total race time ÷ average stint length.
- If one stint is 3 fuel runs of 50 min each, stint time = 3 × 50 min = 150 min.
- Average duty fraction for 3 equal drivers = 24 h ÷ 3 = 8 h per driver.
- Rest time after a stint = time until the same driver returns to the car.
- Driver rotation plans must satisfy maximum driving time limits and minimum rest requirements set by the race regulations.
Vocabulary
- Stint
- A stint is the continuous period a driver spends racing the car before handing it to another driver.
- Driver rotation
- Driver rotation is the planned order in which team drivers take turns driving during the race.
- Rest window
- A rest window is the time between the end of one driver stint and that driver's next stint.
- Double stint
- A double stint is a driving period that covers two fuel or tire cycles before the driver change.
- Fatigue
- Fatigue is the decline in alertness, reaction time, and decision quality caused by physical and mental strain.
Common Mistakes to Avoid
- Dividing 24 hours equally and stopping there is wrong because real rotations must also fit pit stop timing, fuel range, traffic, night conditions, and regulations.
- Assuming longer stints are always better is wrong because fatigue can increase lap time loss, missed braking points, and crash risk.
- Ignoring rest time after a night stint is wrong because circadian rhythm disruption can make recovery slower than during the day.
- Planning driver changes independently of pit stops is wrong because an extra stop or slow change can cost more time than the rotation saves.
Practice Questions
- 1 A team runs average stints of 2 hours 40 minutes. How many complete stints fit into a 24-hour race, and how much time remains?
- 2 Three drivers split the race equally. If Driver A completes two 2.5-hour stints and one 3-hour stint, how many more hours must Driver A drive to reach an equal share of 24 hours?
- 3 A driver is fastest in daylight but has slower reaction time after midnight. Explain how an engineer might adjust the rotation while still protecting rest time and meeting driving limits.