In many countries strikes hit the public transport sector from time to time. Public transport strikes are important for transportation research because they can impact upon the perceived reliability of public transport services. Moreover, the traveller's most preferred alternative is removed from the choice set. The traveller is forced to make up his mind about his preferences; doing so may induce a shift from inert, habit-driven behaviour to rational behaviour. In this paper we review 13 studies of strikes in the public transport sector, discuss criteria that determine the kind and size of the effects of a public transport strike, and present the results of a survey carried out after a short, unannounced railway strike in the Netherlands. Our survey confirms the results of other studies. In the short-term mainly captive travellers are affected; these are mostly commuters without alternative modes of transport who are highly inflexible in their departure or arrival times. As a result, on average 10-20% of the trips are cancelled. Most travellers switch to the car (either as driver or passenger) and as a result road congestion increases. Longer-term effects include a decrease in market share for public transport, which various studies estimate to be between 0.3 and 2.5%. The effect of a strike on public transport rider-ship can be temporary or permanent, depending on the type of strike and the policy response to it. © 2001 Elsevier Science Ltd. All rights reserved.