The other day when walking back to my car at the end of a work day, I've noticed a father and his kid exercising and running on a pavement. The pavement had a walking area and a raised bicycle area. The kid while running did a zig-zag kind of running jumping in and out of the bicycle lane. The dad kept telling him to stop. I thought the dad was a killjoy , I thought it was fun and started running like that to my car.