Interaction design

This is an everyday phenomenon on our street; people fiddling around with the parking meter to buy a parking ticket. In this case there were six people together trying to figure out how that machine works. I could take some nice shots because they have been standing there for several minutes. In this article we are going to examine the usability of the parking meter people use every day.

You can see from a distance that there is parking meter over there, so that is not the problem; people can find it! Now lets have a closer look at the parking meter.

Anarchy of buttons

If you look at the machine it is basically total anarchy from an usability stand of view. There is no clear hierarchy and all the information is presented in the same way.

Mapping

You can argue that the four buttons on the right below are mapped together and that operating the machine should be done in that area. So we could argue that the mapping of the buttons is nicely grouped. The feedback however of using these buttons occurs diagonally, as far as possible.

Colors

The first button is the green button, which confirms your transaction and makes your payment final. Then there is the yellow buttons, that allows you to choose between two ‘parking fares’; one for the main street and one for the less busy roads. Why yellow? The same goes on with the blue button that sets the time span for which you want to buy a ticket. Each push gives adds ten minutes, so for the maximum parking time (which is two hours) you need to push it how many times? Exactly, twelve times. And the last button, red, is the abort / stop button, that is pretty clear, but when you want to use it you have to turn it. So the function of the last button is different from the other three.

Order

It starts with the green button, that should confirm the payment and settings. It would be most logical at the end of the process, definitely not on the beginning! In this case you first have set the parking time below and then go back up to confirm, makes sense? No. The order of the yellow and blue button (choosing ‘fare plan’ and ‘duration) seem logical. The red button at the end suggests you can only stop / abort at the end, but in reality you can stop at every moment. A placement next to the other buttons might be more logical.

Iconography

All four buttons do not have any icon, by this you force users to read an instruction. Secondly the missing icons don’t inform the user how to operate the buttons, should I push, pull or turn it?

Paying

You pay in two ways; with coins or with a card called ‘chipknip’.

Mapping

Both payment methods are close to each other at the top of the parking meter. Beside the good point of clustering the payment methods is that the display that gives feedback about the amount is in close proximity. But there is one little button lost between the operation buttons (below) and payment methods. It allows you to request the balance of your card. It would make a lot more sense if this is placed in close proximity of the card inlet.

Color

Both payment methods are not distinctive at all; they have the same color as the rest of the machine. The round ridge around the coins insert and the cavity of the ‘chipknip’ inlet give user the only information that there is something different out there. Only the ‘lost’ button stands out because it is made out of aluminum an is shiny. The result is that this button is more distinctive then both payment methods, while those are likely to be the most important.

Order

It is positive that the payments methods are placed next to each, this gives the user the idea he can choose between payment methods. In respect to the overall hierarchy it is not logical to place the payment at the top, since that is the last step of the whole process. I know that coins have to fall down and that this is the reason why it is put on top but that is technically speaking, from an usability point of view it does not fit in the overall picture.

Iconography

The icons are not used consistently; two are white icons on a black background which gives them a lot of contrast. But for the coins is chosen for a small piece of paper that show which kind of coins can be used. The icon for our ‘lost’ button is clear but could be even better when it would show the same ‘card’ icon as above to confirm that this is meant for the same card.

Explanation

What you see often with products that have a poor usability is that notes get attached to it to ‘explain’ to those ’stupid’ users how the machine has to be operated. In this case a lot of space is taken by the explanation of how the parking meter should be used. They could have used that space to design the interface with a logical hierarchy that does not need such a manual. In this case even the manual is inconsistent in ‘mapping’, ‘colors’, ‘order’ and ‘icons’.

Redesign

Some people might think that is easy to criticize existing products without showing alternatives. In short notice we want to show an alternative interface that should allow people to buy a ticket quicker and with less frustration.

Do you have an alternative for this parking meter? If you have an idea, sketch or render mail me and I will attach them to the post.