In a perfect world it looks like it will work fine but what happens when you get some kid in there jumping around and such?,(reply>), Ya, exactly like that. Except these are super complicated and change directions. More ways for them to jam.,(reply>), @fin screenname <br><b>and it jams in place trapping people inside.</b><br>You mean like regular elevators also tend to do? I am sure that there still is a lot of work, but it is a reasonable and promising system for high buildings.,(reply>), and it jams in place trapping people inside. I understand you have to start somewhere but this will not be ready for prime time for a while to come.,(reply>), That's where safety checks come in