How about a the Washington DC Metro Subway with the 7000 Series cars. I think it would be interesting
Here is picture of the 7000 series train fo the Wmata. I think it would be possible to do this since the older series trains look more like the M7 that runs on the Long Island route
i should of put this inTSW2020 forum also https://www.wmata.com/schedules/maps/upload/2019-System-Map.pdf