My husband rode his bike to work as usual during the blizzard on Sunday. He has a heavy steel bike with 28" Schwalbe Marathon Plus tires; no studs. For him, riding in the snow was fine, and he rather enjoyed it. Me - I was not able to get much further than around the corner on a similar, but lady's frame bike under the same conditions. So I think it really depends on the person, and how comfortable they are with slippery conditions, how good their balance is, how capable they are with emergency braking, etc. I am sure that some cyclists can cycle in the snow on a road bike with skinny tires, while for others even studded MB tires would not be sufficient to make a safe commute possible. Everyone needs to experiment for themselves...