In the best case, sidewalk slabs tilt and settle unpredictably from frost heaves and water movement, and it only takes a small step between two slabs to trip an

In the best case, sidewalk slabs tilt and settle unpredictably from frost heaves and water movement, and it only takes a small step between two slabs to trip an able person. If a sidewalk is maintained at all the lifted edges will be ground level, a yearly process. Just one example of routine maintenance that I notice.