I don't think the purpose of the confirmation is for lane change purposes.
It makes more sense for it to be for route purposes.
Few questions they should be able to answer based on the :
I noticed that the distance from the exit where it asks you to change to the lane is not fixed.
- Did I suggest this lane change for taking an exit/following a route too early?
- Did I pick the right of the two exit lanes?
- Was the fastest lane suggestion really faster?
- Is it a faster lane but there is another reason why the driver didn't accept it? (Bunch of trucks ahead on the faster lane)
It has varied from .9 miles to 2.5 miles
Sorry but none of the proposed questions can be answered by requesting acknowledgement of lane decisions made by the AI. Some will choose to override, some will accept no matter what and some will randomly choose between the two. As the human intervention cannot be counted on as required, nor the reason for the intervention determined, it cannot be used to determine optimal outcome, which is required to determine whether or not the AI decision was optimal and therefore used to improve the AI. You need to have a clear measure of the quality of the outcome for machine learning to work properly.