Another option, if switching to another channel doesn't work and the wifi isn't bundled into a cable or other router, might be to switch to wifi using the 5ghz band. I think 802.11n and ac use that? That avoids the locomotive interference if it's related to UP's 2.4ghz use. Unfortunately, you probably would have to buy your own router and possibly upgrade the network hardware in your computers etc. to make that work, and many phones can't use the high band.