Where are you? Personally, I very rarely drive to trails, I try to find something within riding distance. There are a surprising number of trails throughout the GTA. For downtown folks, the Don Valley south of Millwood has lots of trails and a dirt jumping track. For people further north, King City has a cluster of trails off Jane (not that busy but some of the climbs have switchbacks that cross the descent so pay attention). Dundas Valley has lots to explore. I am sure there some in Milton/Bolton but like I say, I try to ride what's close and only drive if I have too so I've never gone looking for them.