Designing complex systems is complicated. Sometimes there are interactions between the pieces which don’t quite join up, customer journeys which turn out to have structural obstacles. Some of that can be obscured or avoided through good interface design, but sometimes the underlying ugliness just pokes through.

This screen marks the successful end of a transaction. This screen irritates me immensely. This screen is an inadvertent illustration of last week’s post – swimming ducks and ungainly paddling cannot easily be separated.

Transport for London ticket machine showing "Your Oyster card has now been updated. Thankyou for using oyster. Next time why not top up online?"

There is nothing particularly wrong with this screen as a screen, but it makes an offer which it cannot fulfil. The transaction which the screen acknowledges and suggests would be done better online – the renewal of a bus pass – is in fact one which can’t be done online at all. So there are two pretty obvious questions. The important one is why it can’t be done online, the intriguing one is why it suggests it can.

The superficial answer to the first question is that bus passes can’t be bought online because buses are not equipped to load a season ticket on to an oyster card. There’s no terribly obvious reason why that should be so. There would be a data storage requirement to hold details of pending tickets, but a fairly minor one, and the functionality otherwise needed is already contained in the ticket machines on buses. But though it could work that way, it doesn’t. I have no way of knowing for sure, but I suspect that there is a gap in the system architecture somewhere, that the basic design wasn’t fully thought through, and that now it feels too hard to fix that gap, pretty minor though it ought to be.

So it can’t be done. Why then add insult to injury by patronisingly suggesting that it can? Pretty obviously because that’s a completely generic end of transaction screen, which lacks the basic logic to use the transaction which has actually been undertaken to drive what gets put on the screen. Maybe the people who do ticket machine design have no connection with the people who do web design. Maybe a train-focused organisation (and ticket machine) has forgotten that they run rather a lot of buses too.

Trivial though all this is, I think it it tells us something important. There are smarter ways than TfL so far seems to have found for glossing over a hole in the service. But no amount of gloss can get round the fact that the hole exists. In the end, the only way of fixing the hole is to fix it. Design is not a veneer – and just as important, veneer is not a design.