An orthotropic deck is like a special kind of floor for big bridges that helps hold the weight of cars and trucks. It's made of really strong materials that are arranged in a special way to make it even stronger. Instead of just being flat like your kitchen floor, the orthotropic deck is kind of like a little hill – it has a raised area in the middle so the cars and trucks can drive on it safely. It also has special ridges on it that help stop the cars and trucks from slipping around. When you drive on a bridge with an orthotropic deck, it feels bumpy because of all the ridges, but it's much safer than a regular flat road!