Tim Hardwick, MacRumors:

Apple Maps received several notable improvements in iOS 15, including new details in cities, an interactive globe, and enhanced driving directions. It also gained a feature that has long been available in rival map apps – the ability to set leaving and arrival times for driving directions.

The goal is to have a realistic driving time for future trips, based on predicted driving time for the time of day you specify.

In the past, to get this, had to use Google Maps. Glad to finally have this feature come to Apple Maps.