What are those black rectangular boxes being installed in the center of the roads?

My coworker says they are doing contruction near Lombard, IL. The are making grooves in the roads for these black boxes which are covered in black rubber. These boxes are being implanted in the center of the road where a median would be. What are these boxes? What are they for?|||My guess would be some sort of sensor, although I can't imagine why they would be installed in the middle of the road in the median...





Is this city construction or highway construction? If it's highway, you might consider contacting IDOT and asking someone if they know what it is.





http://dot.state.il.us/directory.html





I looked on thier site, but didn't see any projects in or around Lombard including I-88 and I-355.