Many people have long assumed that the grooves on escalators are there to prevent people from slipping off the moving stairs, but there’s more to it than that. As the steps circulate, the grooves sync up with a comb plate at the top. The comb plate gets locked in by the grooves, which blocks items like clothing, shoes and litter from being sucked in and jamming the escalator. There are also brushes along the sides of the stairs to sweep away debris. Aside from their mechanical purposes, the grooves allow spilled liquids to drain off the surfaces, making them less slippery and decreasing the chance of falls. If you’re someone who lives in fear of escalators, you should be happy those grooves are there. There is, however, one item that's being banned from many escalators: Crocs. It seems that the popular sandals are known for getting caught in the steps, which is why places like Disney World have banned Crocs on their escalators.
