Good fare gates make it harder to forget to pay by accident (or misunderstand how), but don't slow riders down.
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See Tokyo, where the gates open instantly, and tickets can go in in any orientation (and stacked, if multiple).

Oct 17, 2017 Β· 1:15 AM UTC

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My first DLR trip in London was a Tube (has faregates) to DLR (doesn't) transfer. Walked up huge stairway 2x after forgetting to tap out.
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Genoa metro also has faregates at some stations but not others.
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