Best answer by rikkster
Yes, the maps can be removed to regain storage space. Across from the map you've downloaded, you should see a trash can icon, tap on the trash can and this will remove the map.
Some devices perform map deletion a little differently. Tap the three bar menu icon at the top left of the screen and select 'Download Maps'. Tap Manage. Select the map you want to delete, then press the Delete button at the bottom of the screen.