I'd love to see the old 40-60s generation of EMD E series locomotives (TA, EA, E1, E2, E3, E4, E5, E6, E7, E8, E9). We have some Freight versions of the EMD series (Clinchfield and the soon to be Santa Fe F7 addon for Cajon Pass). I don't have the biggest memory of their proper routes, but it would be nice to see some heritage and honestly, highly charming locomotives. I've provided a link to a potential route but tbh, any route featuring these old school trains would be amazing. Burlington-Rock Island Railroad, Chicago, Burlington and Quincy Railroad (The Burlington Route) Chicago, Rock Island and Pacific Railroad
The California Zephyr would be great to see on a CB&Q route, as would the Pioneer Zephyr or other streamliners from the Burlington Route. Perhaps a route set in Chicago could be done and include CB&Q commuter passenger trains, freight services, and Zephyr long- distance passenger services.
This could be a good route set in the early sixties because CB&Q had a steam program that lasted from 1959 until October of 1965 and they had two steam locomotives for steam excursions like 4-8-4 no. 5632 and 2-8-2 no. 4960 and after the president of the railroad retired and Lewis W. Menk took over he saw no interest in running steam so he ended the program and the locomotive was sold to Richard Jenson and in the mid 70s the 5632 derailed and they couldn't get locomotive back on track so they had no choice but to cut it up for scrap but CB&Q 4960 still operates to this day on the Grand Canyon Railway and I think this route and these 2 locomotives would be great add ons.