An account in Cook County, Illinois

I was driving home from my shift at UPS at about 4 a.m. last night. Traveling east on 95th street, most likely before Lagrange road, but I am not certain of which main cross street I was near, because I normally don't take 95th home. I was still in a heavily wooded area. As we were driving something darted out in front of me, perhaps a block or so ahead, it ran across the street from left (north) to right. I thought it could have been a person, but it ran across the street really fast, like someone with those fancy prosthetic legs. As I approached the area, I slowed down to see if there was someone there, but no person was in sight. Like I said, it was tall, thin, and ran fast, like it only had to take a few steps to cross both lanes.