Navigation of the great god, want to ask next do intersection turn left, no u turn this information how to express it,
I saw some people say that online gives two kinds of methods:
Turn left (1) "prohibited", "no u turn"... The information as additional data in the intersection node, dynamic judge whether routes of violate the rules and regulations;
(2) the original into a corner four small nodes (if the intersection is n road intersection, it will be split into small n nodes), such ban turn left, turn around... Can express it,
If split into small nodes, will waste a lot of storage space?