The Georgian vicar whose ideas could have saved Thameslink passengers from misery

London Blackfriars: not a Thameslink train in sight. Image: Getty.

The Reverend Thomas Bayes was born in Hemel Hempstead, Hertfordshire, in 1701. He grew up in London’s Southwark, and died in Tunbridge Wells, Kent in 1761. Had he lived 300 years later, a railway running from Hertfordshire to Kent via London Bridge would have been rather useful to him. And if the people who currently run that railway had paid more attention to him, everyone on the route would be a lot happier.

The Thameslink service links commuter towns to the north and south of London via the city centre. After a major timetable change this May, the network descended into chaos. Instead of the intended massive increase in services, the service through London collapsed.

Things got so bad that Govia Thameslink Railway (GTR) had to hire extra security staff to defend train crew from angry passengers. GTR’s CEO announced his resignation, although he’ll stay in place until the company finds someone willing to take on the poisoned chalice.

So what happened? First, some background. In the 1980s, British Rail (BR) reopened a disused freight line across London. This allowed BR to shift commuter services away from terminal stations, and free up peak hour space at St Pancras and Blackfriars.

This scheme worked so well that the railway went for a second round. This programme was called Thameslink 2000, after the year it was supposed to be finished. It’s nearly finished now (that’s another story). The timetable change was supposed to benefit from the new infrastructure.


Instead it collapsed. London Reconnections has outlined the underlying issues: in short, new trains were delivered late, so drivers didn’t know how to drive them; when GTR took over the franchise in 2014 the previous operator hadn’t been training new drivers, so it’s been playing catch-up; GTR’s training programme relies on drivers working overtime, which many of them don’t want to do; some new tunnels didn’t get handed over until far too late; and GTR didn’t transfer drivers to new depots in time. This meant that many drivers weren’t qualified to drive the new trains along the new routes in time for the change.

Some people might have decided to cancel at this point. But GTR had a cunning plan.

For a train to carry passengers, it needs to have a driver qualified to drive the route that it’s on, a driver qualified to drive the train, and a driver qualified to carry passengers. These don’t have to be the same person, so if you must, you can have three people in the cab, one of whom is qualified to do each. This isn’t ideal; but it’s safe, and it works.

GTR worked out that – between the drivers it had who were trained on the new trains, the drivers it had who were trained on the new routes, and the not-passenger-qualified drivers who had tested the new trains before they entered passenger service – it had enough drivers to run the new timetable by doubling or tripling up in the cab.

But it didn’t. Which is where the Reverend Bayes comes in.

The Reverend Thomas Bayes. Image: Wikimedia Commons.

If you’re working out the number of drivers you need based on traditional probabilities (statisticians call this ‘frequentism’), you look at five factors: the total number of trains needed, the number of drivers qualified for each part of the route, the numbers qualified for the right trains, the number qualified to carry passengers, and sickness/absenteeism rates.

Then you can work out the number of trains to run, based on the number of people likely to be around and qualified. On the evidence we’ve seen so far, GTR appear to have done this, and found that they were, narrowly, capable of running the service.

But there’s a problem here: people don’t come in percentages. Either you have a whole train driver or no train driver at all. And if you don’t have a train driver qualified to drive the train to Finsbury Park when it arrives at London Bridge at 7:30am on a Monday, then your whole timetable is stuffed.

Agent-based modelling is a more complicated way of looking at things than simple probability. But it has a huge advantage over simple statistical models, which is that it can deal with lumpy problems like train drivers. It requires a lot of hard maths, of the sort pioneered by the Reverend Bayes.

You use this maths to set up simulations of what will happen if you try and run the trains you have on the routes you have, using the drivers who you have. So your computer becomes a gigantic nerdy train simulator game, running the entire train timetable thousands of times, and seeing what happens each time you try to run it.

The conditions are slightly different each time: on run 3, the driver who’s off sick is Alan from Luton who is qualified to drive to Brighton but not Maidstone; on run 15, it’s Barbara from Brighton, who is qualified to drive to London Bridge but not Cambridge. The closer you can match the simulated agents to your real roster, the more accurate the simulation is.


Using this model, GTR would have found that having the right number of qualified crew is no use in itself: one person in the wrong place at the wrong time can make the whole thing fall over, even if there’s another qualified person on shift, because that qualified person is an hour’s cab ride away.

Because they didn’t do this kind of modelling, they took false reassurance from their data showing that they had enough crew. The first time their assumptions were put to the test was the first day of the real timetable – when it all fell to pieces.

If GTR had used agent-based modelling to test the new timetable, they would have had to ditch it at the last minute, which would have been horribly embarrassing. Maybe that’s why they didn’t do it. But looking back, it would have been much less embarrassing than what actually happened.

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Barcelona’s car-free “superblocks” could extend lives. So will they catch on elsewhere?

Barcelona. Image: Getty.

The world’s biggest cities have larger populations and higher economic outputs than some countries. But as they grow in size and complexity, cities are also facing thorny challenges that threaten the health and happiness of residents. Congestion, pollution and a lack of community spaces have become major drags on people’s aspirations and experiences of urban living.

In response, cities must manage their resources and priorities to create sustainable places for visitors and residents, and foster innovation and growth. Enter Barcelona – the capital of Catalonia, in Spain – where a bold stroke of urban planning first introduced “superblocks” in 2016.

Image: ISGlobal/FAL.

Superblocks are neighbourhoods of nine blocks, where traffic is restricted to major roads around the outside, opening up entire groups of streets to pedestrians and cyclists. The aim is to reduce pollution from vehicles, and give residents much-needed relief from noise pollution. They are designed to create more open space for citizens to meet, talk and do activities.


Health and well-being boost

There are currently only six superblocks in operation, including the first, most prominent one in Eixample. Reports suggest that – despite some early push back – the change has been broadly welcomed by residents, and the long-term benefits could be considerable.

A recent study carried out by the Barcelona Institute for Global Health estimates that if, as planned, 503 potential superblocks are realised across the city, journeys by private vehicle would fall by 230,000 a week, as people switch to public transport, walking or cycling.

The research suggests this would significantly improve air quality and noise levels on the car-free streets: ambient levels of nitrogen dioxide (NO₂) would be reduced by a quarter, bringing levels in line with recommendations from the World Health Organisation (WHO).

The plan is also expected to generate significant health benefits for residents. The study estimates that as many as 667 premature deaths from air pollution, noise and heat could be prevented each year. More green spaces will encourage people to get outdoors and lead a more active lifestyle.

This, in turn, helps to reduce obesity and diabetes and ease pressure on health services. The researchers claim that residents of Barcelona could expect to live an extra 200 days thanks to the cumulative health benefits, if the idea is rolled out across the city.

Space to play. Imag: Mosa Moseneke/Unsplash.

There are expected to be benefits to mental health, as well as physical health. Having access to such spaces can stave off loneliness and isolation – especially among elderly residents – as communities form stronger bonds and become more resilient.

Stumbling blocks

It was Salvador Rueda, director of the Urban Ecology Agency of Barcelona, who first championed the introduction of superblocks – and he argues that the idea could be used in any city. Even so, authorities looking to expand the concept in Barcelona or beyond will need to be mindful of some concerns.

Changes like these require capital investment. Even as the car-free streets are transformed with urban furniture and greenery, the remaining major roads will likely have to accommodate heavier traffic.

Nothing comes for free. Image: Zvileve/Flickr/creative commons.

Further investments in local infrastructure – such as improving surrounding roads to deal with more traffic, or installing smart traffic management system – could be required to prevent serious congestion. Then the question remains, how to finance such investments – a higher tax rate is unlikely to be popular.


What’s more, whenever a location becomes more desirable, it leads to an increase in property demand. Higher prices and rent could create pockets of unaffordable neighbourhoods. This may lead to use of properties for investment purposes and possibly, displacement of local residents.

It’s also worth noting that Barcelona is an old and relatively well-planned European city. Different challenges exist in emerging global cities across Asia, Africa and Latin America – and in younger cities in the US and Australia. There is a great deal of variation in scale, population density, urban shape and form, development patterns and institutional frameworks across the cities. Several large cities in the developing world are heavily congested with uncontrolled, unregulated developments and weak regulatory frameworks.

Replicating what’s been done in Barcelona may prove difficult in such places, and will require much greater transformations. But it’s true that the basic principles of superblocks – that value pedestrians, cyclists and high quality public spaces over motor vehicles – can be applied in any city, with some adjustments.

Leading the way

Over the history of human civilisation, great cities have been at the forefront of innovation and social progress. But cities need a robust structure of governance, which is transparent and accountable, to ensure a fair and efficient use of resources. Imposing innovation from the top down, without consultations and buy-in, can go squarely against the idea of free market capitalism, which has been a predominant force for modern economies and can lead push-back from citizens and local businesses.

Citizens must also be willing to change their perspectives and behaviour, to make such initiatives work. This means that “solutions” to urban living like superblocks need to have buy-in from citizens, through continuous engagement with local government officials.

A man speaks at a public consultation on the Eixample superblock in Barcelona. Image: Ajuntament Barcelona/Flickr/creative commons.

Successful urban planning also needs strong leadership with a clear and consistent vision of the future, and a roadmap of how that vision can be delivered. The vision should be co-developed with the citizens and all other stakeholders such as local businesses, private and public organisations. This can ensure that everybody shares ownership and takes responsibility for the success of local initiatives.

There is little doubt that the principles and objectives of superblocks are sound. The idea has the potential to catch on around the world – though it will likely take a unique and specific form in every city.

The Conversation

Anupam Nanda, Professor of Urban Economics and Real Estate, University of Reading.

This article is republished from The Conversation under a Creative Commons license. Read the original article.