Well, first and foremost, I guess the main benefit is saving a lot of money. If you use your car everyday to go to work and go shopping it can cost thousands of dollars where I live. Between the fuel, insurance, parking fees, mandatory yearly checkup (with possible repairs which are even more costly), the bill climbs pretty fast!

And it can be such a pain to drive a car in the city. Traffic jams, Red lights every 2 minutes (we all get that unlucky day), finding a free parking spot, waiting at gas station when there's a penury (they are bound to happen!).

Using a bike or simply walking is comparatively hugely cheaper obviously, but also quite less frustrating in urban areas at least.