Even though Seattle has a pretty good-sized bike community, it is hampered (in my humble opinion) by traffic, weather and hills. There's not a good intra-city bike route system and the system that exists serves mostly the northern part of the city. Those of us southward have virtually nothing, so riding on the roads as a beginner commuter is often way too intimidating since once downtown, you have no choice but to ride on busy city streets. The first reaction I usually get is that I'm crazy to deal with the traffic. The weather is often cold, rainy and windy. Maybe May - October there's good weather, but you have to have decent rain gear available at all times and know how to use it. Many businesses don't have good bike storage facilities (secure, out of the weather, or none at all) or showers and locker rooms for bike commuters. Hills - lots of them. I even have to arrange my grocery store runs and neighborhood runs according to what hill I have to go up. Most people are not in shape to even ride around the neighborhood on a bike, lots of walking and bike pushing would be in order, so why bother, not to mention the sweat factor if one wants to go out and socialize. Having a good transit system than allows bikes to be stored (bike racks) and used is very important in this case. Even sometimes I don't want to ride all the way, esp. if I'm sick or have to be somewhere quickly.