information of where the train is at any given moment. and it passes on information about switches and passes and other trains and you can combine that into control stations on the ground and put into one simple graphic showing the engineer how fast he must get on the brake ss and if the engineer does not do that then all of the information through the compoourtcom computer system will take over the train and even stop it to avoid a problem. that's the positive side of it. there's actually congressional analysis of this done just a few years ago. it could pretty much get rid of all the train to train collisions we've heard about. it should keep us from having anymore of these switching