Donald Norman, a key thinker in user interface for objects has written the following:

There are several important fundamental principles of interaction design that are completely independent of technology:

• Visibility (also called perceived affordances or signifiers)
• Feedback
• Consistency (also known as standards)
• Non-destructive operations (hence the importance of undo)
• Discoverability: All operations can be discovered by systematic exploration of menus
• Scalability. The operation should work on all screen sizes, small and large.
• Reliability. Operations should work. Period. And events should not happen randomly.

All these are rapidly disappearing from the toolkit of designers, aided, we must emphasize, but the weird design guidelines issued by Apple, Google, and Microsoft.

We should think similarly about how these interaction designs apply in an urban setting, especially for travelers. For instance, think about bus stops …

• Visibility – what do people see about their environment, do they know where the bus stops, what happens when they get on (where does it go), when does it operate, how long will they wait?
• Feedback – when they go to the bus stop to wait, does a bus come?
• Consistency – does the same thing happen every time, or does the bus not come on weekends? Do they pay for it the same way each time?
• Undo – can I get off the bus and get back to where I started?
• Discoverability – can I figure out where the bus goes based on the bus stop sign?
• Scalability – does the same information apply at all stops, or do some stops have more than others?
• Reliability – does the bus come on time?