It is early days, but London’s new public bike hire scheme appears to be on the way to being a great success, or a jolly good wheeze, as mayor Boris Johnson might put it.

London now has around 5,000 ‘Boris bikes’, as they have been nicknamed, at over 300 hire stations and 43,000 journeys were made in the first week alone. Officially, the initiative is called the Barclays Cycle Hire scheme, but Johnson looks set to become more associated with the scheme in the public mind than the corporate sponsor.

The scheme aims to encourage people to cycle in central London by offering bikes for hire. The bikes are slow, heavy and very distinctive – presumably to discourage theft – and there is a complicated pricing structure, presumably to encourage users to make short journeys by bike.

Charges include the cost of a membership key, which speeds up bike hire, at £3, an access fee £1 for 24 hours, £5 for a week and £45 a year and a usage charge. The first 30 minutes are free, and then it is £1 for an hour, £4 for an hour and a half, rising to £50 for 24 hours.

While the scheme will encourage some to cycle instead of taking a bus or a tube, it could also raise road safety questions, if it leads to more people unused to London’s traffic and road layout trying to get around by bike.

In recent years, cycling in London has become increasingly popular, due to a mix of high public transport fares, growing interest in cycling as a hobby and the realisation it is often the quickest way around London.

However, most regular cyclists wear helmets and coloured clothing, whereas the Boris bikes are aimed at the new or occasional cyclists, such as commuters travelling a short distance from a railway station, or tourists.

The scheme also raises some questions about the politics of environmentalism. It purports to encourage cycling, an environmentally friendly means of transport, but does the carbon footprint of setting up and maintaining the scheme outweigh any green benefits?

London’s previous major, socialist Ken Livingstone, made a more radical and arguably more beneficial reform, when he introduced a congestion charge on petrol and diesel powered vehicles entering central London a few years ago. But this is unpopular with some, even though it is unlikely to be revoked now.

A congestion charge does not create a nice image compared to people cycling, so in the ‘greenwash’ stakes, a voluntary public bike hire scheme trumps cutting traffic by taxation.

And to be honest, like recycling household rubbish, or not using plastic shopping bags, it also fits most peoples’ preference for being seen to be doing something environmentally virtuous, rather than something truly significant, such as not owning a car.