Acknowledgements

Back in December 1997, I gave a raw version of this document to my friend Jürgen Leitz who made a couple of useful suggestions on what to take out and what to explain in more detail. One of his main points has been to add some examples and case studies. More than one year later, I distributed some copies of a new draft at the Automated People Movers Conference, APM'99, in Copenhagen and I am grateful to Bill Flanagan and Markus Szillat for their feedback. Bill Flanagan ``polished up'' the language and Markus Szillat made some important critics that led to an extensions of the economical aspects of the MAIT system. I am also thankful for the lively discussions with Joachim Gräf. They are in fact responsible for the MAIT implementation section. My special thanks go to Jody and James Weygand whose corrections and remarks helped to considerably improve the quality of this document. Finally, I would like to thank all the people who contributed and shaped this work through numerous discussions.