4. Because it's often faster for short distances

In the city I used to live (Eindhoven), I often had the situation that trips were shorter by bicycle than by car. This happened especially when I had to move around the city center, where they have many one-way streets (one-way for cars only) and many red lights (you don't always have to respect those when on the bicycle).

It sucks though when it's around between 1 and 5 degrees Celsius and it's raining...