WMBD stands for World's Most Beautiful Drive, which is what president
Theodore Roosevelt proclaimed Grand View Drive in
Peoria, Illinois is. At the time, it may well have been as I doubt there were too many roads that could be driven during his presidency. By now I'm sure that more beautiful drives exist.
Besides being the call letters for the Peoria CBS TV affiliate, WMBD are also the call letters for 1470 on the AM radio dial.