One of the realities today of driving into a city like London is the congestion charge, a tax on vehicles entering a specified zone the boundaries of which are clearly marked by signs like the one here.

It’s probably largely similar to other cities which operate congestion charging schemes as a means aimed at reducing traffic congestion during certain times of the working day and/or raising local tax revenue (how you see it depends on your own perspective of such schemes, whatever the politicians might say about it).

The London congestion charge has been in force for nearly eight years and I’ve simply become accustomed to it now: if I want to drive into central London, there’s this tax I have to pay, that’s how I think about it. £8 a day which increased to £10 a day on January 4, 2011, although the overall congestion charging zone was reduced (PDF map) by a significant area on that day, too, so a kind of balancing.

And I do drive into central London, into the congestion charging zone, once or twice a week. I’ve usually paid the charge each time by SMS message from my mobile phone: I send a text message to a special number and I get an automated SMS acknowledgment back along with a PDF receipt to my email address. I find all of that extremely convenient, if fiddly and manual. Actually, I’m impressed by how Transport for London has organized the payment system which also includes paying at machines located throughout the charging zone, paying on the website or by a phone call to an automated voice response system, as well as a billing system if you have multiple vehicles and drivers toing and froing in the charging zone. Whether you like the congestion charge concept or not (actually, I know of no one who does), having multiple choices on how you prefer to pay is good for everyone.

Yet the one thing that hasn’t existed is a means of automated payment based on some kind of automatic recognition of a vehicle when it enters the charging zone, meaning you don’t have to do anything to ensure you pay. I’ve thought about that especially on the couple of occasions last year when I forgot to pay the charge and once when I didn’t realize I’d entered the charging zone. In each case, I got a penalty – £60 a pop if I paid the fine within two weeks (£120 otherwise). Ouch!

So when I heard late last year that an automated payment system would be introduced on January 4, I signed up immediately for CC Auto Pay.

The benefits of this are self-evident, in particular no more forgetting to pay the charge (and thus not attracting penalties), and paying a reduced charge of £9.

How CC Auto Pay works seems pretty simple to me even though there’s some sophisticated technology behind the scenes.

What happens is that when you cross into the charging zone automatic number-plate recognition cameras, like the ones you see here, snap your number plate. If your car registration number matches a CC Auto Pay account, the charge is applied and your account debited.

Then, at the end of each month, the congestion charging administrators tot up your charges and automatically bill your credit card for the charges you’ve accrued in that month. Pretty simple from a user point of view.

What I also like about how Transport for London has implemented this system is that it uses technology and a process that’s already in place – automatic number-plate recognition – rather than going along the route of special gadgets you have to attach to your windscreen that trigger a sensor when you pass by, as is often the case in countries that operate toll systems. So no additional and costly physical infrastructure to install.

Worry-free congestion charging. Works for everyone.