Apollo: The difference between pnc-junction and junction

[math715]

the hdmap proto, there are pnc-junction and junction. I want to known the difference between pnc-junction and junction.

[jmtao]

• junction is a rough area around a junction/intersection. We mainly use it for perception ROI.
• pnc-junction is the junction concept specifically for Planning module. It uses the stop lines of traffic signs(traffic light, stop sign, crosswalk, and etc) as the boundary of the junction. The boundaries are used for decisions and planning in Planning module and must comply with traffic rules.

[math715]

I understand, Thank You.