Question: I have an odd question that I am a little embarrassed to ask. For financial reasons we are moving to a non-Jewish neighborhood outside of an eruv (an enclosed area in which it is permitted to carry objects on Shabbat). I saw that you dealt with a question about riding a train on shabbat and hoped you might take it a step further. I already checked with another rabbi about issues with traveling on a train. He mentioned he once saw a shabbat pass for Liverpool public transit before the war, so apparently they did it there. If the only way I can get to schul on shabbat is riding a train and I have a pass to ride the train, would you think it would be permissible? I know what you said about marit ayin (the appearance of doing something wrong), but would it help if there are no Jews in the area or if I wore a baseball cap over my kipa? And here's the clincher for me. Is there any way to wear the train pass so that I can carry it onto the train where there is no eruv. I would not let anyone in the schul I'd attend know how I got there, but it is a question of being alone for shabbat or attending schul.
Answer: My sense is that since other than marit ayin it would be permissible (except for carrying), I'd say that if you can punch a hole in the pass and wear it like a necklace that should pass halakhic muster. I think, though, that you should tell at least one friend from the shul what you are doing. What would happen if weather knocked out train service? You would need somewhere that you could stay in the neighborhood until after Shabbat (and also possibly need to borrow money for a taxi or get a ride back home).