They are very useful for parking posts. How else would we know how terrible it was that car A is parked 3 feet over the dropped curb which is perpendicular to the neighbour's drive but on a higher level than OP's house but the bollards are on an angle and the front garden is 2 feet at one end at 5 at the apex, with car B overlapping the path slightly and C rocking gently on it's roof.