In order to clarify appropriate methods for providing traffic information in the event of a disaster on railways, which information sources were expected and judged to be useful by passengers of the Osaka Monorail at a time of the 2018 Northern Osaka earthquake, and whether the use of such information was related to passengers’ satisfaction and dwell time at stations, were examined using a questionnaire survey. The results showed that from various information sources, broadcast announcements and announcements from staff bringing public information were expected, used, and evaluated as useful. Moreover, useful public information was shown to increase the passengers’ satisfaction and reduce dwell time at stations. On the other hand, the evaluation result is significantly worse than expected, and it was revealed that some people used informal information from friends and acquaintances. It seems that railway companies can increase customer satisfaction and improve the appropriateness of passengers’ behavior by improving the way of broadcasting and announcing, and promoting the use of public information.