In the 16th century it became the practice to plant trees along country roadsides, a tradition that continued into the 20th century. Unfortunately, roadside fatalities have put a curb to such close implantations. Where possible, trees like the ones above are gradually being replaced by trees planted at greater distances from the pavement.
la sécurité routière: road security
une chaussée: a road, a pavement
une trajectoire: a trajectory, a path