Painting Event - width of the brush - 50 or 100 meter?

What is the width of the brush?

It looks like 50 or 150 meters: LARGE one, very Large!

What is the idea of such a large width of the brush in the Painting Event of Streetquest?

Even if I am returing in this event quite diffrent way to home (50 meters far) I am stil painting the same path on the map.