I had started a thread about the trail a few months ago and had that same question. Even though I ride a road bike, I think they should leave it as is. If it were still rails, I'd say pave it, but that area has been left to nature for about 40 years now. Never mind the runners either, I'm not siding with them, there are lots of unpaved places to run. It's just that the area is wild, and how many wild areas are there in The Bronx?