MILWAUKEE - The bridges in the busy Zoo Interchange are in such bad shape, they have to be torn down immediately. The DOT first noticed there was a problem with the bridges back in August and quickly posted new weight restrictions. Now, after months of thorough inspection, they've decided to immediately tear down and replace those bridges starting in December. The work should be finished by Memorial Day. The Zoo Interchange is the busiest in the state, with more than 350,000 vehicles using it each day.