What will passenger companies do once their F59PHIs, F40PHs, P40DCs, P42DCs, MP36PH-Cs, MP36-3S', MP40-3Cs, F59PHs, F50PHs, P32-8BWHs, P32AC-DMs start to wear down? Will GE or EMD make a new four wheel axle locomotive or will they use six wheel axle units? I was thinking of maybe a GP70DCe, GP70ACe or GP70M-2 and either a ES40DC-BWH or ES44DC-BWH. What do you guys think?