Revolving doors also have problems: Once they start spinning, they force the people to keep a certain walking speed. People who cannot keep up the walking speed may fall and hurt themselves. People in a wheelchair cannot use revolving doors. The same probably applies to blind people. Revolving doors cannot be used in an emergency: They cannot be passed at a fast speed. For all these reasons, many countries have rules that buildings must also have other doors. In hotels and public buildings, is usual to find "push" doors either side of a revolving door.