Paying Tolls at Severn Bridges

This story on BBC news site about the payment methods at the Severn Bridges in Wales strikes one with surprise. As the story states, the bridge is an engineering design and construction marvel but the payment methods are still unbelievably archaic. Pray, given the sophisticated payment mechanisms available in the UK, why would its managers insist on either cash or a prepaid card as the only means of payment for the tolls?

To my mind, payments by electronic means would be preferable both for audit purposes and security especially since the story mentions that the passage is used by millions of vehicles annually. As Mr. Bryan Seaward states, " The bridge may be high tech but the payment methods are stuck in the seventies".

This still does not explain why the inflexible payment system was instituted in the first instance. Perhaps they ought to think of the danger that is involved in transportation of all that cash from the payment booths to the banks as they determine when to amend the laws to allow for electronic payment.