Many of you may at one point have had a coin rejected when paying for your parking. You try the coin a second time and it still doesn’t work, so you vigorously scratch it against any flat metal space, typically above the coin slot, and lo and behold, the coin works (I’ll explain why this works further down below)
Yesterday, I took this picture of a parking pay point at Cavendish Square shopping mall:
Not only do they ask people not to scratch the paypoint with coins, but they also threaten to hold them “liable”.
As you can see from the scratch marks above the coin slot, it doesn’t seem to work!
I took the picture, because it was in stark contrast of another parking paypoint I saw in Johannesburg at the Gautrain Hotel.
Faced with the same problem of paypoints starting to look grimy from scratching, they took a very different approach:
Rather than threatening customers with liability, they simply put a steel plaque up so that people could scratch to their wrist’s content.
It immediately strikes any customer as clever, but it is also done in the spirit of being helpful. At the same time, the paypoint company solves a major headache. Genius in simple solutions.
Explanation on why scratching coins work
All electronic equipment has the habit of failing, and coin readers are no exception. As most people are aware, a simple reboot can fix many problems, whether it is your PC acting up or your Wi-Fi router delivering slow internet for no known reason.
With early electronic parking meters, resetting the machine was a major headache. A technician had to unlock the machine and it would take several minutes before it’s rebooted. As these technicians also weren’t too good at customer service, they would keep people waiting, which would be even more frustrating if you had already thrown half your coins in.
To make matters worse, technicians would start rebooting machines even in cases when there were genuine problems with coins (such as chips, bends etc).
A professor from UCT’s Electrical Engineering department, who had done some work with remote monitoring of vending machines was called in. The original idea was to have GPRS modems added to each machine and have the machines rebooted remotely, without needing to wait for a technician.
The professor suggested something much simpler instead:
1. Only reset the coin reader (i.e. restart the driver program running it), not the entire system
2. Have low-skilled on-site staff be able to do a restart with a simple metal tag
A solution was thus built with a cheap magnetic reader (similar to the ones that come with your home alarm system) mounted on the inside of the machine, near the coin slot. Any staff member could use his metal tag to restart the machine by rapidly moving the metal tag back and forth in front of the magnetic reader, thus inducing a voltage change that could be measured by the magnetic reader. (The metal tags were slightly magnetized, thus just moving it in front of the reader would normally start the reset process).
RFID type tags were originally considered, but as they would get lost and would cost a lot more, simple metal tags won out.
Of course, staff members quickly realised that they could use ordinary coins, although they looked different from the standard metal tag (which looked more like a laundry machine token than a coin)
Thus, whenever someone had a problem at the paypoint, they’d call someone, who would then come and simply take the nearest coin and rub it vigorously in front of the magnetic reader.
As you can imagine, this behaviour caught on like wildfire!
And THAT is why you may be held liable for scratching the coin at Cavendish.