Weekends in London are becoming a nightmare of public transport challenges. Every week we’re notified of which tube lines will be closed or partially closed at the weekend. The list often seems cheekily long. The whole Victoria Line is often closed, the whole Circle Line, portions of the Jubilee Line, parts of the Northern Line, bits of the District Line, individual stations here and there, and a crucial stretch of the Piccadilly Line which means that you can’t reach Heathrow Airport by tube. They close bits of the Docklands Light Railway which mean that travellers can’t get to City Airport. And now the Northern Line is entering a phase where half of it will be entirely closed at weekends until the end of 2011.

In addition to the stoppages which are advertised, there are plenty which aren’t. Yesterday I had visitors who left my house to return to Cambridge. Knowing that the local tube line was out of action, they went to get an overground train to Waterloo. But there were no overground trains either, though there was no warning about this in the station foyer, and they didn’t discover it until after they’d validated their tickets. The only option was to go a long way round, with several tube changes, to King’s Cross.

Arriving there, they found that the middle part of the London-Cambridge journey was to be ‘replaced by a bus’. Slowly they made their way by train and bus, with a half-hour wait on a rural platform in the rain before the final bit of train journey. At Cambridge Station, there were no buses ‘because of a fire’, and they had to walk into town. And all this was on an ordinary weekend.