Replying to PVC RIALS DO THEY WORK?

I build and maintain the park at my local hill. I was just wondering how well pvc rails hold together. I saw some this summer at camps in whistler but they looked gheto. What about them breaking when its cold as hell out. we get realy fucking cold here. What size and wall thickness should i look for. we already have 5 or so metal rails and im thinking because it would be cheeper to use pvc. i want more rails in my park. jusrt wondering what yall thaught?