Utilizing arrow signal information in Planning

[TakaHoribe]

In this discussion, I would like to discuss how we can use the results of traffic arrow signal recognition in Planning, as well as the necessary modifications to the Lanelet2 format to support it.

On the recognition side, arrow signal recognition is performed, and the message definition includes information about positions such as UP_LEFT_ARROW, UP_RIGHT_ARROW. (Related PR)

An example of the intersection with the UP_RIGHT_ARROW traffic signal is below.

However, on the planning side, left and right arrows are only supported. You can see the actual code here. The cause of the limited support is that Autoware can not get information on which lane corresponds to each arrow.

Currently, the intersection lanes only have tags for straight, left, and right (see the lanelet2_format_extension in Autoware for detail).
One solution is to expand the map tags to align with the message types used in recognition.

Any opinions or suggestions are welcome. Thank you!