Drawbridges are special.
There are hundreds of drawbridges in the United States spanning canals, rivers, bays, and other bodies of water. Many are fifty years old or older. As these bridges age, cities must make difficult choices about whether to invest in the significant repair work required to keep them operational. Chicago, for example, one of the drawbridge capitals of the world, has over 60 drawbridges, only 43 of which remain operational today.