I only recently noticed that apparently all sidewalks in my city have a very slight slope towards the street. (I found out when I pushed the shopping trolley from the near supermarket full of bottles of water.) That the sidewalk has this slope makes sense – it allows the rain to flow away to the gutter. I wonder if that is common practice in the construction of pavements, gutters, and streets. And if so, that is pretty ingenious. I very much love such smart and effective "knacks" in #infrastructure.