The biggest fault of the entire Japanese system is the stoppage at night. 24 hour service is not the solution and is one of the reasons the services there work very well. But I don't understand why they don't have a replacement system. In Philadelphia the (smaller) system is completely replaced by buses. In other countries the trains run 24 hours but only Friday nights and weekends nights which could increase the use case of 90% of riders to 95% of riders.