Today is the 15th anniversary of the introduction of Oyster travel cards in London. Which also means it is the 15th anniversary of the start of the creation of a huge pile of money left on unused Oyster cards.

Back in 2012 it had reached £55 million. Now it’s up to £321 million.

Here’s what Lib Dem London Assembly member Caroline Pidgeon has to say about it:

There is no question that Oyster has been an incredible success.  It has made travel more convenient and provided real flexibility for millions of people.

It is now so established that it is hard to believe how we managed before its creation 15 years ago.

However, as we celebrate Oyster’s success we should not overlook the staggering rise of dormant Oyster cards, creating an immense cash mountain for Transport for London.

The balances and deposits on Oyster cards that have not been used for a year or more now stands at more than £321 million.

The total amount left on dormant Oyster cards is soaring, almost certainly in part due to the increasing number of people who have switched to contactless payment.

TfL never stops bombarding us with advertisements and information campaigns, but highlighting this cash mountain is one issue that they remain incredibly quiet about. It is time TfL devoted far more time and energy telling the public how they can get their own money back.

TfL also needs to ensure that a weekly cap on Oyster is introduced as quickly as possible.   While there has been a weekly cap on contactless payment from the very beginning we still have no precise starting date for when Oyster will have a similar cap.

Boris Johnson promised that a weekly cap on Oyster would be introduced in 2015.  It is appalling that we are still waiting for TfL to treat Oyster and contactless payment travellers equally.

In case you’ve got unused money on Oyster cards that are no longer in use, here’s how you can get the cash back.