Festive travel: For doom and gloom, change at Finsbury Park

You are accustomed, of course, to the transport system in the UK shutting down almost completely on Christmas Day and Boxing Day. But tens of thousands of rail passengers hoping to travel last weekend endured long, stressful journeys because of a phrase that is even more depressing than "rail replacement bus": overrunning engineering works.

They are not equal inconveniences: while changing from a train to a bus and back again is a faff, particularly with lots of luggage, children and other annoyances, at least you know about the disruption in advance and can plan how best to handle it. The chaos into which tens of thousands of post-Christmas travellers were plunged last weekend was unplanned and much tougher to deal with.

Rail passengers had already been told that two of the 10 busiest stations in Britain, London Euston and London Bridge, would be closed over the weekend. But two other top-10 stations, King's Cross and Paddington were closed on the day because planned work on the high-intensity lines radiating from the capital to the north and west overran.

On Boxing Night when I heard that East Coast Trains would be turning around at Finsbury Park, my one-word reaction was "Mayhem".

Network Rail attempted to shift passengers, staff and trains from a major London terminal that can handle 100,000 passengers on a busy day to a dingy suburban station with four platforms that struggles to handle the daily average of 17,000 passengers. The aviation equivalent would be to say: "We've problems at Heathrow, so let's move everything to Luton". It doesn't fit.

I can understand a temptation to think "we'll sort it out on the day," but the evening of 26 December should have seen Network Rail booking every spare coach in the east of England to run a shuttle service linking London with Peterborough, Leeds and York . While journeys would have taken twice as long as the train, sitting on a bus going somewhere is preferable to queuing around the block outside a station in London N4 temporarily closed because of overcrowding.

Over at Paddington, passengers planning to make an escape on Brunel's wonderful Great Western railway were instead told to take the Bakerloo Tube to Waterloo and try from there.

The pretty way between London and Bristol starts in Waterloo and goes via Clapham Junction, Woking and Basingstoke. Thereafter things improve, with a cruise through the Wiltshire Downs, a glimpse of the Westbury White Horse and a bucolic journey along the Avon Valley. Fares are often cheaper than First Great Western from London Paddington, reflecting the fact that journeys take an hour longer than the high-speed trains. Usually. But on Saturday, even with delays after a signal failure at Southampton, it was better by way of Basingstoke.

Looking for closure

Ahead of the mayhem, the chief executive of Network Rail had been boasting about the ambitious festive plans. "Making the railway better is what we aim to do every day," said Mark Carne. "Our investment programme this Christmas, the biggest yet, is fully focused on delivering a better service for passengers, With an 11,000-strong army, we will deliver a huge amount of work."

When the efforts of Mr Carne's troops began to unravel, Network Rail sought to minimise the impact by saying that the hiatus was "a small part of a massive amount of engineering investment taking place over Christmas". But the twin failures at London termini were precisely the elements that stood to cause maximum misery.

Mr Carne and his colleagues at Network Rail may not relish their next meeting with the Transport Secretary, Patrick McLoughlin. In what may prove a robust conversation, they must explain why Saturday's disruption was so poorly managed – and why the engineering work didn't go according to plan in the first place.

Expect a move towards longer-term closures of lines – which sounds worse, but in fact has merit. With advance warning travellers can arrange alternatives. That could be a different, slower rail route; taking the bus; or, for commuters, working from home (or at least pretending to). A longer "possession" of a line for engineering allows much more work to be done, because the actual process of closing a line to keep staff safe consumes a lot of time. Spreading out work through the year also means resources can be spread less thinly: the Christmas workforce of 11,000 was split between 2,000 sites.

Big Ben, big profits

While thousands of people woke up in the wrong places on Sunday morning, the tourism minister, Helen Grant, was telling the world how tourism in Britain is set to thrive in 2015. Not if the unfortunate tourists stuck in London over Christmas tell their friends how dismal an experience it proved.

The near-total shutdown of transport rendered day-trips to Windsor or Greenwich out of the question, so the West End, South Bank and Westminster were crowded with tourists. The main link between these areas is Westminster Bridge. Right through the festive season, criminal gangs mocked the Met by setting up shop on the river crossing. On Christmas Day, they were selling snacks from filthy hot-dog stands, and on Boxing Day a half-dozen illegal gambling games were in progress in the shadow of Big Ben – making a fortune by fleecing tourists. Try running such a scam within yards of the White House, and see how you get on.

To see villains acting with impunity in the heart of the capital is a national embarrassment. The London Mayor must resolve after New Year to tackle this shabby side of the city.