Erie RR crossed PRR and NKP at Plate Interlocking which had a separate interlocking facility until the structure was destroyed in a wreck after which the interlocking signals were remoted to AK tower at the NKP/DAV crossing adjacent to Bennett Road in Dunkirk. AK was removed probably twenty years ago by NS.
B&LETCO used underpasses to cross those lines. Leaving Dunkirk for Fredonia the cars ran down Central Avenue which went under the steam railroads. B&LETCO ran along Doughty and then under the steam railroads. There is a map on page 124 of Bill Gordon's book on the B&LETCO.