Here is a simple Kato Unitrack DC layout with three separate lanes. Two double crossover tracks enable switching between all lanes. Two PRR engines split the passenger cars of the Broadway Limited. At one time the Broadway Limited used electric GG1 engines for part of the trip and then switched to diesel engines for the remainder of the New York-Chicago run. This layout uses a GG1 for half of the cars and an EMD E8A diesel for the rest. The SCARM layout file is linked at the bottom.
Download SCARM layout here.
Pennsylvania Railroad Broadway Limited by Kato