"How much?" A question about imageability and seams in transport fare systems

(Something of a follow-up post to the recent transport informatics survey.) A recent conversation with Jarrett Walker, a consultant based here in Sydney, popped up the following thought. Jarrett, experienced in metropolitan transit systems, was thinking through ideas around fare pricing given the new possibilities enabled by fully automated systems.

Design of fare structures have been fundamental to transit planning for years, attempting to define charges for journeys in equitable yet efficient fashion. Balancing those last two factors mean that the basic problem is often shot through with tensions - e,g, richer suburbs paying less than poorer, due to zoning often based on radial principles emanating from a central core, and so on. Jarrett knows more about that than I. Whatever, existing systems based around zones etc. do at least usually have a stated, consistent pricing for journeys that can be easily communicated, even if not necessarily agreed with.

However, Jarrett was wondering about some emerging thinking he'd heard around the possibilities of new smart card-based, integrated ticketing systems, and the sense that varying prices could be generated in real-time, based on variables like distance, time of day, number of passengers on board, overall running costs of the system at that point, demand etc. That you wouldn't know the actual price you'd been charged for that particular journey and that actually, you needn't. You just swipe the card and conduct your journey, in the knowledge you'll have pre-paid to a certain amount, or pay a monthly bill subsequently. You'll trust the system will charge you fairly, of course, and you could see the breakdown of costs at the end of the month, or when your pre-pay card needs topping up, and so on.

(As an analogy, you'd contend that few people really know/care the exact cost of each one of their phone calls, for instance. The payment is represented by sometimes complex monthly plans, based around a number of free minutes/texts that are bundled, a certain number free within a network and so on. Obviously, some do know what they pay each time, but hasn't the general tendency has been towards bundling into monthly packages, abstracting away from pricing the actual individual calls at time of connection? With a pay-as-you-go model for those without financial security.)

So the drift towards an ongoing service model of variable pricing bundled into pre-paid or direct-debited packages seems an option. With an increasing deployment of GPS devices in all vehicles and RFID-based tracking of passenger entry/egress, it seems likely that some transit systems will try this out, in effect neatly hiding the complexity of pricing from the citizen.

This is partly also due to the sheer complexity of pricing systems e.g. Sydney's train system alone has over 120 'fare products', apparently. Multiply that by ferry, bus and light rail. This fare complexity is largely a result of attempting to be equitable, and at the moment the complexity is shared by both system operator and customers.

However, Jarrett wondered whether citizens might actually want to understand, or engage with, their public transport system a little more deeply. That pricing is one way of perceiving the structure of the transport system, and that's something that customers might innately want to do. He thought that it might be important to perceive how the system works, at least as expressed in fare structures. It's a map of the city, in a sense. In a city like London, the topography is overlaid with a mental model of the zones, which take on a kind of meaning over and above fare products (I proudly lived in zone 1, would more or less travel to zone 2, and so on.)

When he asked me the question about whether perceiving the sysetm was important, I immediately thought of the importance of seams and imageability.

Seamfulness, some long time readers will know, is a particular interest here (and of others, like Anne Galloway and Adam Greenfield.) It holds that a desire to hide complexity via an apparently perfect, hermetically-sealed product can actually mitigate against a successful informational system.

A classic example here is the iPod, which given its undoubted success also indicates how complex the argument is. That success is down to its carefully linked system architecture with iTunes as well as its rigorously reduced interface and seductive aesthetic. And yet its alleged undoing is also to do with its 'perfect' design, in that batteries are difficult to replace (meaning most people don't) and that it's a music experience that can't be tweaked or modified much. You could argue that if the iPod showed its seams a little more, it would be more malleable as a device, and even more engaging as a product experience. Doing that without damaging its seductive sheen and usability would be tricky but potentially rewarding. That old "beautiful seams" ambition.

The other reference is of Kevin Lynch's concept of imageablity, from his pivotal book The Image of the City, which I've always thought should apply to system design - the ability to perceive the system around you (visually, spatially, intellectually) and be left with a strong 'image' of its structure. Also known as legibility. A few years ago Peter Lindberg developed the idea specifically around software architecture, and I've subsequently thought it an essential feature of good system design (whether the system is a building, a music-playing device, a transport system or indeed Grand Theft Auto.)

So it seems to me that the ability to show/hide structural detail is fundamentally important element of a system. It enables the legibility of the system. And that showing a bit more detail, if carefully and sensitively articulated, can only engage the user further. Not necessarily exposing minute technical detail - though a handful will always want that - but enabling perception of the basic ambit, structure, joints, seams, influences, and so on. It certainly enables that form of engagement known as adaptation or even hacking - not in the pejorative sense of the word - but in the sense of building upon systems and extending them - as we've seen with transit systems that do begin to expose their behaviour.

And of course, as these and similar pervasive systems migrate into many spheres of life, deciding how visible to make parameters, motives and controls becomes even more important. Will hiding such intricacies reduce civic engagement in urban information systems? Or conversely, will its seamless design lead to increased take-up of services like public transport and thereby greater civic engagement?

What do you think? I'm aware that I'm posing the question to a particular audience, but do you think that, in this case, a transport system that has a choice to hide the potential complexity of a fare system should do that? Or should it reveal its complexity either through having set fares or by displaying the calculated fare on the spot? Does convenience trump legibility?