Andrew from Pittsburgh on 7/16/2022 6:10:59 PM:
I rode the trail from Pittsburgh to DC in June and would say that the trail surface for about 1.5 miles downstream of Dam 4 (between MP83 and MP 84.5) is downright dangerous. It appears that some resurfacing was attempted and was a complete failure. This area was always a bit soft, with the trail being sandy. Now, though, there is the new resurfacing material on top, but something has caused there to be a large washboard effect. I have ridden washboard roads, and this is similar to that, only the distance between the peaks and troughs is maybe 10 times larger, so the bumps are very rough. And this was difficult to see with the new surface and the shaded surroundings, so you would hit these sections with little to no warning. The old surface, while bad in places, was at least easier to visually determine the surface quality.
Also, further downstream in other sections of resurfaced trail, patches where there was erosion were done with a fill material that was much coarser than the original resurfacing material, but the same color composition. So again, you would come upon these sections of very rough trail with very little time to react to the changing conditions.
If the NPS could at least provide some signage both for the long section around MP84 and the short patch areas, that would go a long way to mitigating the hazard that these rough surfaces present.