There is a small but interesting exhibition in the Science Museum in London. Called 'Our lives in data', it tells us how our data is collected and what is done with it -- or could be done with it. And it challenges us to think about how much data we are prepared to give away.

In my previous article on this subject, Our lives in data: privacy, I looked at this topic mainly from the point of view of personal privacy. Bit the data on how people travel, while obviously of a personal nature and therefore concerned with privacy, it also has other ramifications.

In London many people use an Oyster card:

Oyster card, by Terry Freedman — Oyster card

London buses no longer accept cash. You **have** to use an Oyster card, or a contactless card.

The car contains credit for travelling, and details of individual journeys. If you register your card, it will track your individual journeys.

Here are a few examples of journey patterns shown via Oyster cards, and the implications one can draw from them. These were all taken from a display at the Science Museum.

Oyster card data pattern of a person who has taken a week off

Travel data pattern of someone without a regular commute

This kind of information can be, and is, used to plan the layout of stations. The following photo shows the new layout of Bond Street tube station in central London. You can't see it very well, but the gist of the story is that Transport for London analysed the sort of data shown in the photographs above, and from that were able to deduce how many people used each tube line. They then planned the layout of the station accordingly.

The advantages to Transport for London of all this data are obvious, in terms of planning. No doubt it's useful for the police too. But what are the advantages to ordinary commuters of registering their Oyster card? After all, they could travel anonymously just by topping up their card, using cash.

One advantage is that, if you lose your card and have to get another one, you can transfer credit from the lost card to the new one, so you don't end up out of pocket -- apart from the £5 it costs to buy another card.

Also, if something goes wrong, you can obtain a refund. For example, a few years ago i got on a bus to ask the driver if this was the right bus for a particular area. It wasn't, so I had to get off and get on a different bus -- but not before the Oyster card reader on the bus read my card (even though I hadn't actually touched my card on the reader), and deducted the money. I was able to obtain a refund because it was obvious from the travel data from the card that I'd apparently had two bus journeys within 30 seconds of each other. I like travelling on buses, but that's some going even by my standards!

Another reason though is that you can prove you were somewhere else when a crime took place. Or, to be more accurate, your card was. (But if someone stole your card and used it to travel somewhere to commit a crime, the travel data would show that the journey was out of the ordinary in terms of your travel history.)

This has a bit of a personal resonance for me. Back in the 1970s there was a knock on the door one evening. Two policemen were standing there, and they took one look at me and said "Ah. You look like the person we'd like to interview. Where were you on the night of...?"

This is what I looked like by the way:

I asked why, and they said that a girl was beaten up in the lift (elevator) of the apartment block in which I lived. The person who did it was young, and had long hair and a moustache.

Fortunately, it turned out that on the night in question I had been driving miles away, and had had to call out the AA to look at a fault on the car. That's the Automobile Association, by the way.

Also, having been on jury service a couple of times, I've seen that the accused usually claims they were nowhere near the scene of the crime. But if that was true, how could they prove where they were not?

There's also the fact that the police can trace the movements of a victim of crime using both the travel data and CCTV.

For these reasons, the more data there is about where I am, and the more CCTV coverage is, the better, as far as I'm concerned. I suppose you could say that I value my safety, and my freedom from being false accused of a crime, more than I value my privacy. I see it as a compromise. The transport people, and potentially the police, know where I've been and where I am, so in effect I've traded that information for a bit of security and convenience, and to avoid loss of money if my card and I become separated.

But I don't announce on Facebook or Twitter etc where I am: what would I have to gain by doing so?

In the next issue of my newsletter, Digital Education, I'll be looking at privacy. If you're interested in that, why not sign up (it's free):

Postscript

The technology -- and artificial intelligence -- found in London's transport is fascinating. See, for example, the information about SCOOT in the article Delivering the future of London’s traffic signals.

Also, you might like this view from the front of a Docklands Light Rail train, which drives itself: