Running on a trail is better than in urban areas
Though it might be for a somewhat embarrassing reason, running on wooded and natural trails are probably better than city streets. People in the city are usually more strict about people using their restrooms. However, when you're out at a park or a heavily vegetated area, no tree or bush or public bathroom is ever going to discriminate you for having to go. Running on a nice trail is more relaxing than the concrete jungle anyway.