Question Regarding Chicago Card (Transit Info)

Factual Questions
1

The CTA (which is public transit) in Chicago has a relativly new thing called the Chicago Card. It is like a speedpass. You just wave it at the fare box and it rings you in. You don’t have to put it in a slot or slide it thru anything.

Well I’ve used mine for a week and it worked fine.

Question is…Today the bus was crowded and people were pushing and my card was in my pocket and as my leg got pushed up by the fare box it beeped and took my fare. The card was in my pocket. I was wearing Dockers Slacks.

So the question is how does this thing work? If I walk pass a turnstyle without going thru will it beep? How close do you have to be?

Evidently you don’t even have to take the card out of your pocket.

2

It’s an RFID (radio-frequency ID) tag. The farebox emits a radio signal that the fare card picks up, causing it to respond by returning a signal containing the data stored in the tag. The tag in the card is powered by the signal it recieves. Thus, the range is rather short. It seems unlikely that the card would be activated in a situation where you didn’t intend to go through the turnstile, as you wouldn’t be that close.

Mobil SpeedPass keychains and “pet microchips” also use the same technology, as well as some security/ID bages. Many retail inventory control (anti-theft) stickers use a similar technology, although those are much simpler.