We'll be visiting Houston in the next few months and wanted to see if you would recommend using the metrorail (I will have my 3 elementary aged girls with me)? It would be easy enough for us to get on and off from where we are staying, and it stops at several destinations we would be going to, but I'd rather not expose my kids to things like a bunch of crack-heads having a gang bang in the back of the train... Or have a crazy homeless person screaming at us during the ride...