I don't know how useful they would be here in PA, depends on the cover I suppose. One area in northern Maine that I hunt has hundreds of miles of remote atv trails. I can tell you that there are some good inaccessible grouse covers that can be reached through the use of an atv that would be a very long (20mi) walk without one. I personally don't know of anything like that here in PA.
There are more snowmobile trails I believe than atv trails. Lately there hasn't been much snow for the trails. Alot of the trails are on state forest or park land. There is a good map of trails for the Forbes state forest. Not sure where you are located. If there's enough snow for snowmobiling I'd suggest not hunting them. Only for the reason that they might be heavily used. But still public land. Jmo
I use them on gamelands and state park lands I hunt and they make for quick,quiet entry into areas I want to hunt. Except for late archery rarely is there enough snow to worry about.
I often see deer and bear on the trails, they can get around quicker and use less energy on these clear paths. Large game and turkeys also find new growth along the open areas on the sides of these trails.
I worry more about being run over by deer on the paths than motorized vehiclesI