From 1923, the first race, until about 1980 (or so) the Le Mans 24 Hour Race was run on ordinary public roads that were open to traffic 363 days of the year. Yes, the road was made wider, and the curves were smoothed out, and there was Armco everywhere.
Hawthorne's 1956 lap was the way it was except for the official practice day, one day before the race. In earlier years there wasn't even an official practice day. Practice at Le Mans ALWAYS involved avoiding the French farmers riding/driving whatever, whose routine ABSOLUTELY would/could/should not be altered by the racers. The French are like that, you gotta love 'em.
So it is 1971, the summit year of speed at Le Mans. It is 2 days before the big race. There you are, Gaston Dubois, aged 75, on your bike, on your way home after work to embrace your beloved and quaff a glass of the local beer, in the village of Les Hunaudieres.
Imagine the wind blast from the two Porsche 917-30s, 5.4L flat-12, turbocharged, 1100 bhp apiece, the two cars three feet apart, going by you at about 225mph (or more) on the Mulsanne...