Owl service

A night service or an owl service is a public transport service which operates through overnight hours, while most people are asleep. Many cities operate such services, mainly using buses but in certain cases using trams (or streetcars), either in addition to or in substitution for ordinary daytime services or rapid transit rail services which may shut for maintenance or due to lack of passenger volumes at night.

Night-based services may be differently branded compared to daytime services, such as in London, where overnight buses are prefixed with an "N" for "night". Another common way of distinguishing them from their daytime counterparts are dark-colored line numbers. Some cities apply a different fare structure from their daytime services. There are also services that allow users to alight at a requested place of stopping rather than at specific locations, in deference to passenger concerns about safely walking long distances.

24-hour, continuous rapid transit operation is practiced in some cities, most notably the subway in New York City, which essentially renders night services unneeded. Many of New York City's buses also have 24-hour operation; and around the world, night services may be provided by virtue of 24-hour services on daytime routes, as does Berlin on its "Metrotram" routes. Where they exist, night service is generally much more limited in geographic coverage than daytime services, with fewer lines and routes over entirely different paths to daytime services; or the night terminus may be in a different place. Networks may run longer routes than daytime services, sometimes combining two or more daytime routes, which may use interchanges to reach the same outlying districts. Night services usually also run less frequently.

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