Alright, so Deval Junction in Chicago is a great example of this - all 3 lines going through Deval - CN, UP-NW, and UP New Line each have lots of grade crossings nearby the junction and on both sides of the junction for each respective line - so, if a train has to wait to cross, where do the dispatchers hold it so that it doesn’t block grade crossings?
In most cases, the Special Instructions will cover such situations. As an example, the Special Instructions in the IHB employee timetable states that westbound trains over a certain length will stop short of Cottage Grove Avenue if they are not cleared through Dolton Crossing.