While Japan has regional ticketing systems and companies, they did standardize nationally on supporting 3 major prepaid transit cards (pasmo, suica, icoca) so m

While Japan has regional ticketing systems and companies, they did standardize nationally on supporting 3 major prepaid transit cards (pasmo, suica, icoca) so most rapid transit and regional transit are low friction enough to just tap in and tap out. China has done the same with T-Union. I suppose with NFC contactless payment, a plausible future state is just supporting credit card payments everywhere, though of course this doesn't solve the monthly pass problem.