I think the crux of the problem is that Clipper tries to make CalTrain work like a "user-operated virtual faregate system". I.e., it's designed for BART, and users are supposed to pretend they're on BART. There just aren't any actual gates, you just have to remember. This is a bad fit to a proof-of-payment system.
I can think of two ways of making Clipper actually work well for CalTrain:
- Use RFID on trains to automatically scan cards as people get on and off. (That would actually be a problem for people like me that have a GO pass for CalTrain but keep a Clipper card for other systems, but I think the solution would be to tie GO in with Clipper). This way you really wouldn't have to think about tickets at all (if you set up autoload).
- Or: At least automatically scan cards for exiting the train, so no tagging off is necessary.
- Instead of the simplistic tag-on/tag-off interface, connect Clipper with regular ticket machines that allow you to load up the virtual equivalent of any regular ticket type (one-way to zone X, day pass to zone X, monthly pass, etc). It's a more complicated interface for getting on the train (but the same as buying a paper ticket, anyway), but no tagging off necessary.
Of course, all this would cost money to implement. CalTrain doesn't have it, but the MTC always seems to find the money for nifty gadgets.