With traffic lights, jams, bus stops, etc.. it does slow them down tremendously. Of course bikes can go through jams and lights willy nilly. My job was 6 miles

With traffic lights, jams, bus stops, etc.. it does slow them down tremendously. Of course bikes can go through jams and lights willy nilly. My job was 6 miles from home by car and 45min (some quite stressful), I actually took a longer path (7miles) by bike to enjoy a river path, took me 40min to arrive.