GPS coordinate of the sketchy area? Is going around the West side of Mahattan up North and around to the East side pretty safe?
You wouldn't hit the sketchy area unless you were inside the park and way away from the trails. On street level, there's no danger anywhere. I don't have coordinates for the exact area, but on google maps, it's between Washington and Hamilton bridges (the top two of the cluster of three bridges).
Nice avatar. As an aside, the area we're talking about, under the I-95 Hamilton Bridge, was once the site of a rather large northeastern fight club. They used to stage fights under there because cops wouldn't come in the park, and the constant traffic of I-95 above masked the sound. Another piece of illustrious NYC history.
At some point in the next three years, they will be completely rehabbing that area and building a skatepark!