Improvements to shortcuts computations : consider upstream and downstream nodes

I'm creating an issue to track a old comment made here : https://github.com/a-b-street/ltn/issues/69#issuecomment-2600882440


https://www.openstreetmap.org/#map=17/43.600230/3.902979

Both of those shortcuts aren't *shortcuts* because you could reach the outcome faster by another path when entering the shortcut.

> We could check what's allowed at the exit intersection. From that exit, if the only reachable point is the entry intersection, then it's this simple redundant case. If there's anything in between, then maybe it's still a shortcut somebody would take, but it could be weighted less, based on how "useful" exiting there is.

So I would suggest that you should not only take the first-downstream node of the exit, you should also take the first upstream node of the entry.

Most of the shortcuts shown here would be discarded or changed


For example, this shortcut would never be taken as a car would come from upstream(A) which would give another shortcut



この issue では、issue #69 のコメントと OpenStreetMap のリンクが参照されています。ショートカットの計算コードを探してください。おそらく、グラフ解析またはルーティングを扱うモジュールにあります。上流ノードと下流ノードが現在どのように考慮されているかを調べてください。まず既存のショートカット検出ロジックを理解し、提供されている例でテストして、提案された改善が実際にどのように動作するかを確認してください。

索引モデルが issue の本文から書いたものです。