Because a dog was chasing him across it. Because tu scared him. Because he was depressed and wanted to be hit por a car. Because he saw another Chicken on the other side. Because he was running from the cops. Because Target was on the other side. Because he was running from justin bieber. Because lobos were after him. Because a hunter was after him. Because the Cullens were after it. Because he just felt like crossing the road!!!!
But why did the chicken want to get to the other side? He wanted to cruzar, cruz the road. It makes sense, because sometimes, a chicken has to cruzar, cruz the road.
In a seriousness, the chicken wanted to cruzar, cruz the road to sue KFC for killing its family.