Glenelg, Sunday 12th February 2006


The old trams between Adelaide and Glenelg are wonderful. These trams leave Adelaide centre and reach Glenelg beach in just half an hour. They are nice, old, antique trams, made of wood. In summer passengers cool down by opening a window, controlled by a leather strap.

Accommodation Adelaide

Bed & Breakfast: Glenelg Sea-Breeze
2a First Avenue,
Glenelg East
SA 5045, South Australia
+61 8 8295 3791
It is easy to request the tram to stop: adjacent to every window is a stop button. Press such a button and you'll hear a bell. You'll see a "stopping" sign light up at the front of the tram too. When the tram stops, all doors open. Passengers disembark, doors close and the trams moves on. A clear, crisp interface, direct feedback, well designed.

New trams

The old trams team up with some new ones. These new trams are very modern, make less noise and... have air conditioning. The air co is where things get complex. To open the door the passenger must press a button. That seems acceptable, but the button has a few complications:
  1. The button serves multiple purposes, can serve as a stop button when the tram is in motion.
  2. A colour light shows the status of the button. Red means stop request. Green means open door.
  3. A door only opens when a passenger presses a green light button.
  4. A second push on a red light button cancels the previous stop request.
So, a passenger that presses a red button twice will be disappointed. A passenger eager to get out, ends up with a tram skipping his station.

Violated design principles

One function One button should have only one function. A button on a door should open the door, as simple as that.
Will on might Yes, it might happen that a passenger
  • is at the door,
  • and presses the stop button in error
  • and the tram does not have to stop for other passengers
  • and the passenger wishes to cancel his erroneous stop request.
But all of this is not plausible. It will not happen. So a designer should focus on the most common situation: open the door.
Keep it simple. The design in the old trams was so nice:
  1. A passenger presses a stop button while seated. The tram will probably be in motion, or else the passenger would not be seated anymore.
  2. Doors always open. Just be at the door to get out.
The interface is minimal: one type of button, with one function.
The new design seems to have originated from a too theoretical drawing board, without real world testing.

Explanation does not work

Many passengers panic when they fail to open the door. The conductor will shout some instructions from afar and tells the driver to stop a bit longer. It happens several times on each journey.

Adelaide Metro came up with a solution: Information for passenger at some stops. No passenger will read this information before boarding as the problem of the complex button is yet unknown at the time. There is no picture of a button displaying green light.

Once boarded there is a bit of information surrounding the button. Read the instructions top to bottom and you'll see:


The solution to all of this, get rid of all complexity, back to basics: The design of the old tram was not too bad. A design is complete when... you can't take anything out.

Till next nut,