Here's the extent of rail service to Moffett: [
www.google.com]
I think the pic is old, too; the connection from Caltrain to VTA for the short trip over to Moffett seems to be gone now. So even if the track is still in the street it isn't used. Might be fun to dig up older aerials or topo maps to see if Moffett rail service was ever more than a couple of short spurs.