Several, in position to respond to issues such as yesterday's failure of the points at Farnborough. An hourly Woking to Basingstoke stopping service provided by say four 53 seater coaches is not going to be able to even remotely meet the requirements of commuter stations used to more frequent 8-12 coach trains, so all you do is promise something you can't deliver and strand huge number of people in the freezing cold as they can't board, many of which likely would have just gone to another local station to catch a train (like they are doing now). Obviously not everyone has that luxury, but you can't exactly dictate who can and can't board the bus. Had this happened during the school holidays then it may well have been a different story, such as the upcoming planned closures of three routes during the February half-term week with buses running Guildford to Petersfield, Bracknell to Reading and Staines to Windsor. But with bus and coach companies struggling to staff even their own normal operations at the moment, there simply isn't enough spare drivers locally during term time to fulfil the additional requirements of a mid-week mainline railway closure with any realistically useful amount of capacity that won't see the majority of intending passengers left behind.