Why not a universal transport card for public transportation systems?

As I visited several cities in USA, South, Central America and Canada, I used public transportation in most cities and it almost always involved getting myself a pass or travel card- a credit card sized plastic card issued by different transportation systems for use in their transport network.

1. Washington DC- SmarTrip card
2. Bogota, Colombia- Tullave card
3. Panama City-RapidPass
4. San Francisco, CA- Clipper Card
5. San Diego, CA- Compass Card
6. Los Angeles, CA - Tap Card
7. Vancouver, BC- Compass Card

These smart cards are convenient way to travel in a city's public transport system- they cost 2 to 5 dollars each to procure, then you load money into it and tap them against the sensor while boarding the bus or entering a train station. The sensors deduct applicable fare and let you through. Most places tapping a card costs little less than paying cash- in some cities like Panama the card is the only way- no cash accepted.

I now have about half a dozen different transport cards with me, each left with a few dollars in it. To ensure those dollars don't go waste, I think I should visit all these cities again.

Now, I am left wondering why do we need so many transport cards? When a Visa/Mastercard can work worldwide, why not these smart cards? (Of course Visa/Mastercard provide technology platform and framework using which banks can issue cards, settle amount between merchants, customers etc, GDS platforms exist to sell airline tickets, hotel rooms etc - such a platform may not exist already for public transportation world but that shouldn't stop us) I can probably understand one card at a country level- but if you see above, the state of California itself has at least 3 different cards- LA has TAP, San Diego has Compass, SF needs Clipper. Why can't we make Clipper card work on LA's buses and trains? Why can't we have a universal travel card that works across multiple transportation systems/networks?

Same problem in Australia- Melbourne, Canberra and Sydney all need separate transport cards- one won't work in another network. [Update: I am told Sydney has started accepting debit cards and soon rest of Australia will join soon]

Same problem in India- Delhi Metro, Mumbai Metro, Bengaluru Metro all have separate cards- why can't we have just one?

There're immense benefits of offering such an integrated transport solution. Let us take example of state of California in USA.
1. Cost savings- By having one integrated transport card, it will be adequate to maintain one back-end IT support team,maintenance team, customer care for entire state. No need for multiple teams doing same work in different cities
2. Less cards/Plastic: I am sure fair number of California residents travel within the state and  currently have multiple transport cards- clipper, TAP, Compass etc. They can now maintain just one card. Saves on card cost, better for environment
3. More convenient: Travelers don't have to buy, load and maintain several cards
4. More standardization and reduced infrastructure costs- with one system/cards- vending machines, gates and other infrastructure will be standardized and can drive down cost. Both tourists and residents will benefit.

Complexities involved:
1. Settlement between departments: Money deducted now needs to be settled between different transport systems- but I don't see any concern on this- Most cities are already smart enough to have one card system for all different modes- trains, buses, metro, ferries etc. Within San Francisco, Clipper card can be used on BART, CalTrain, SamTrans and Muni- I am sure there will be a mechanism to distribute deducted cash to corresponding companies. Same now needs to be extended to transport systems in other cities for one integrated experience.

2. One time software upgrade: Sensors installed in various buses, train stations need to be able to the following
-Authenticate the card- that it is genuine, not reported stolen or fake and is issued by own or a trusted partner network
- Check balance- to ensure card has minimum balance required for the journey
- Deduct Balance- for the trip
- Be able to recognize special scenarios- Unlimited ride day pass, Senior/Student concessions etc
- Indicate Go/No Go (If everything is fine Open the gate or show green light, flash error if anything is wrong (like Not enough balance)

3. Clear logic for settlement in case of Day Pass: If a day pass is issued and customer spends half day in one city and another half in another, how to split the money between departments? Based on number of rides taken or time or some such clear logic needs to be agreed upon.

4. Trust: before everything, multiple transport departments should be able to trust each other and willing to work on an integrated transport solution.

5. Fraud detection: Credit card duplication and using a stolen/fake card for big ticket purchase is understandable. But would some try to fake a city transport card to save a few dollars of bus fare? I don't know. But then yes, adequate security measures will be needed to prevent/detect fraudulent cards and usage.

Transport systems in Canada don't even need a transport card- if you have a Visa credit card which are having contact less feature, you can tap the credit card directly on the sensor. Integrated transport card will be good problem to solve- particularly for state of California, home to several tech giants and birthplace of various innovations like driver-less cars, Lime electric cycles and so on.

There is one concern with tapping credit/debit cards during international travel- banks charge very unfavorable conversion rate and a fee for such transactions, so we end up paying lot more than actual fare.

Today we have global sim cards- like TSIM Global which works in 165 countries. [Detailed review of TSIM]. Airlines are collaborating with each other (Star Alliance, One World etc) to share frequent flyer programs and other shared benefits. Credit and Debit cards already work across a wide range of ATMs, merchant outlets and other online systems. So integrated transport card that works across cities (and eventually across countries) isn't a wrong thing to ask.

But one thing still remains- what I have illustrated above isn't a million dollar problem to solve. Yes it costs few dollars more to get another transport card and most people are probably fine with it-if a million dollars have to be spent to make cards work across transport systems no one will probably come forward to spend on it. But I don't think solution is that complex or expensive and would surely payback within years in saved maintenance cost.

What do you think?

City buses around the world * Tips for easy use of London/UK's public transport *