I have always relished the challenges Mother Nature provides. In my many years of all weather commuting, I can count on one hand the times I was uncomfortable because of the weather. To be sure, accurate weather forecasts, especially Doppler Radar, are a real advantage. Dressing properly, being prepared for any change, and having lights and mudguards on my bike are all that I found necessary. Also, since rain and sleet hurt when they hit your eyes, a visor really helps. Glasses or goggles tend to fog up so YMMV.
Bad weather seems to make motorists a bit unpredictable so there is that challenge to deal with. Perhaps you could design something to calm them down.
Have you looked at your project from the infrastructure viewpoint? When snow comes to town, my community's response is to plow everything from the car lanes into the bike lanes. These big mounds take a long time to melt and when they do, all of the messy debris they contain concentrates on the road surface. To me that's a much bigger issue than comfort.