This is a slick one, no time to react… cop sits under the viaduct in the center median, monitors mostly the northbound LaGrange road traffic, just after you pass the 87th street intersection. As soon as you make the sweeping left curve, which is the first viaduct you go under, cop is on your left side. LaGrange is 55mph up to 87th St., then drops to 45. Not always a willow springs cop, sometimes cook county sheriff. They do tag team also, spotter sits under the viaduct, and second cop sits up further, by the Sanitary canal service road. And in summer months, they do run motorcycle cops, too.