The new tiger exhibit at the Cleveland Metroparks zoo, with the highway bridge looming overhead, made me think about zoos who are at least affected (if not defined) by their physical relationship with a highway. Not simply a matter of access to the zoo, but where a highway defines the zoo's lay-out. Many zoos have highways at their boundaries but the zoo remains on one side. But in some cases the zoo has grown across the highway making for some interesting linkages and design issues. At Cleveland there is a clear gateway created by passing under the elevated highway bridge. Dallas Zoo: long broad tunnel that separates one side of the zoo from the other and is used for interpretive signs. Toledo Zoo: a highway separates the two parts of the zoo. More?