The fine is low because the "typical case" is like a long van that's hanging over the line into the hydrant zone or something but doesn't actually block access.

The fine is low because the "typical case" is like a long van that's hanging over the line into the hydrant zone or something but doesn't actually block access. They'd rather have the fine be low for the people who are actually blocking the fire lanes in spirit in order to rake in the money from the people who are only doing it in technicality.