A-10 exits itself once in Montréal, and it also did so in Sherbrooke before some engineer decided to change the easternmost segment to A-610.
A-15 does this three times: in Longueuil to join Pont Champlain, then twice at A-40 in Montréal.
A-20 also does it three times: at Échangeur Turcot, then at the same spot as A-15's self-exit, then at A-25.
A-40 does it five times: twice in Trois-Rivières and thrice in Québec City.
A-55 does this three times: near Magog as it joins A-10, in Drummondville as it joins A-20, and in Saint-Léonard-d'Aston as it leaves A-20.
A-73 exits itself two times, both in Québec City.