Peter Krantz takes Stockholm’s mass-transit ticket machines to task, the main issue being the completely illogical placement of the action buttons.
Lots of ticket machines seem to suffer from UI problems:
Tom Coates describes buying a ticket for the London bus system with an interactive Flickr photo. Note that there’s a similar problem to the Stockholm machine: The first button you press isn’t at a logical starting point but lodged off center and in the middle of a cluster of other buttons. Mike Ellis doesn’t really care for the London machines either.
Boston isn’t immune: Ashley McKee wasn’t even sure how to pay for her transaction and Joshua Ledwell was asked to think way too much for what is almost always a time-sensitive transaction.
Minneapolis - Saint Paul?. Steven Hauser documents the problems with their card system and a disabled Craigslist’s poster was also confounded.
Why stop at mass-transit machines? The parking ticket machines seem kinda screwy too.
If you don’t have one readily available but would like to try a mass-transit interface for yourself: Harold Thimbleby created a web-based simulation of a real London ticket machine while researching material for his book Press On: Principles of Interaction Programming which is a look at key principles of interaction design.
Multi-touch
The solution? Well of course there is more than one but I’d keep my eye on multi-touch technology. It is become cheaper and the iPhone has paved the way for large-scale consumer acceptance of the technology.
First of all the placement of the interactive interface widgets isn’t tied to the physical world - if the machine has to scale with your transit system then the “virtual” interface can too.
Besides placing buttons wherever you like the interface widgets can scale with the person on the other side of the screen. You can capture how fast they tap or how large their tap “point” to enlarge or shrink widgets or even the click areas around each widget to make the interactions more reliable.
And of course, multi-touch is just fun. Seriously, people just have fun using it and I don’t think because it is “new”. It just works and the interactions come naturally which, makes interface elements like route maps or scanning a list of stations more intuitive.
Why not multi-touch?
Accessibility. It is a show-stopper and in my mind the issue is closely tied to that of tactile feedback. This doesn’t mean it is unsolvable though.
There is already technology for “vibrating” the touch screen when you press a button but that’s not enough to print text (or braille) labels on interface widgets (unless you’d like to revert to a world run by Morse Code). Is it possible for a screen to emanate physical pressure, perhaps through heat or forced-air, on your fingers that would leave the impression typically felt by pressing your finger down on printed text?
If multi-touch is a completely foreign concept to you (wha? iPhone?) do check out Bill Buxton’s extensive overview of multi-touch concepts, systems, and research. [^bill2]
[^bill2]: Okay, maybe I wasn’t kidding about that 24-hour network.