Done at night because it is colder. The colder it is the better the grooming.Got a cousin who lives in the Upper Peninsula and worked in the winter grooming state trails. Used a snow cat with heated cab. I think he said he had over 80 miles of trail to tend. Done mostly at night to avoid the snowmobile users.
Wedge
Driving these big groomers is a real trip, all hydraulic steering and it takes some practice.