Application of Departure/Parking Time

Summary:

Is there any documentation covering how the Departure/Parking Time value is applied to Travel Key Travel Estimations? We're attempting to identify whether the configured value is actually being used or not, and we're struggling to see it.

The operating assumption is that, if the travel estimation is 30 minutes and we have 15 minutes configured for Departure/Parking Time, that the travel applied to the activity would be 45 minutes. However, this does not appear to be the case and we need to understand it better.