The Downers Grove control point is unique in the sense where two of the turnouts are parallel to one another. Going east toward Chicago, the turnouts from tracks 3-2 and 2-1 are parallel. In the past I have seen some westbound Metras, after making a station stop in Downers Grove, cross over 3-1. And some eastbound movements on track 1 have crossed over to 3 at that interlocking. But, a westbound move from 1-3 on a single pass and 3-1 eastbound is impossible. A good example is westbound Metra train 1245. When that train completes its run at Downers Grove Main Street, it crosses over 1-2, pauses, then goes east 2-3 thru the interlocking back to the station. A reason for this particular move is to allow easbound 1276 to pass thru before 1245 flips. East Lisle was removed, then reinstalled to accomodate movements during the Belmont project. If a control point were to be removed, personally, I'd remove the East Lisle ones once the Belmont project is finished. Some eastbound freights using the middle track that stop would be in the interlocking, making them useless.