This is it. No more walking on the sidewalk. If one wants to, then he has to jump over the barricade to go that direction!
Maybe they are trying to save the grass. Perhaps, they are trying to save people from harmful, wild animals that hide in the grass. How will this barricade save us from the wild animals? Maybe its an obstacle course? Jump over!
I really cannot figure this out. Only the person who did this would have enough intellect and insight to give the answer.
Admit it, you didn't want to walk that direction anyway.