Each car has two alternating drivers. No driver may total more than 14 out of the 24 hours. Each driver must have at least one hour rest between turns at the wheel.
18 seconds sound clip from the Le Mans (1971) movie soundboard.
You can hear this line at 00:16:47 in the Blu-ray version of the movie.
Quote context
[...]
- There are 55 cars and 110 drivers representing countries from all over the world.
- They will drive day and night, through sun and rain.
- His blood type must be indicated on either suit or crash helmet.
- No one may drive more than four consecutive hours.
- For the first time in the history of this race...
- Yellow means danger. No overtaking.
[...]