Intuitive user guidance - the parkometer

Some days ago we have been visiting a pitoresque little town in northern Switzerland. Having found a parking lot near the center. The parking lot was well equiped with a number of parkometers. Those little machines allowing payment for parking time.

Usual user guidance of such a machine is:

Start at the top. An old fashioned LCD display shows wether the machine is currently in use by indicating the current time. Bellow a slit to drop coins is located. Dropping coins makes the display to indicate the so far payed parking time. Pushing a usually green button below will print the parking ticket to be placed visibly in the car.

There is an other concept for the same purpose. The machines, probably second generation, exhibiting not only a display, a slit for the coins but also a numeric keyboard. This particular parking lot was one of those. Each parking field has a numeric indicator which needs to be entered to the payment machine. The ticket is only considered as a receipt.

However, the location of the interaction elements such as display, green button, slit for coins and numeric keyboard is not really adapted to the new concept.

Starting at the top the display indicates the current time and date. Next the slit for coins is waiting for input. - Really? - Below the coin entry element the numeric keyboard is located and at the very bottom the same green button can be found. So, how does this work?

Starting from the top we start dropping coins which will not be accepted by the machine. Why? - I would guess that you have to drop coins until the desired parking time is payed, enter the numeric identifier of your parking field, then push the green button in order to get a receipt.

Several attempts would not lead to successful payment.

After a while I would discover this little note at the bottom. A little sticker communicating the right process.

1. Enter the identifier of your parking field
2. Drop coins for the parking time
3. Push the green button
4. Take your receipt

Logical? Intuitive?

At least the sticker implies that I am not the only one...