Cycling in London. Photograph: Crispin Hughes/Getty Images

Thanks to the persistence of MayorWatch Londoners now know that Barclays Bank has so far coughed up £13.43m towards the cost of Boris Johnson's cycle hire scheme out of a potential maximum of £50m by 2018. How full should our cup of gladness be?

An upbeat view would be that if the sponsors keeps paying at the present rate Transport for London will eventually receive the full amount due under the terms of the deal (although some of the Barclays money also goes towards the cycle superhighways). Those less intoxicated by the all-pervasive branding, relentless hype and eager applause of Mayor Johnson's media fans might ask once again if the public money spent on the project could have been invested more profitably in terms of encouraging pedal power in the capital.

I'm still in the asking camp. As MayorWatch points out, the Barclays contribution accounted for a pretty small portion of the £119m the scheme had cost by the end of the last financial year (and has bought it a fine heap of publicity in return). But taxpayers' contribution is expected to have more than doubled to £225m by 2016 and hard-pressed London boroughs will be required to stump up some of the cost of the scheme's expansion into their territories.

The price of being a member of the scheme will double too in January. The mayor reckons this will help it to eventually break even, but time will tell if the hike has an adverse effect on membership numbers. Large claims are made for the success of cycle hire, yet research for TfL published in September 2011 (pdf) found that about 30% of the scheme's members weren't Londoners, and that nearly half used the bikes as a commuting alternative to public transport when one of cycle hire's original ambitions was, by contrast, to persuade people out of their cars.

It's worth remembering that Johnson's 2008 manifesto spoke of a cycle hire scheme being secured through "a deal with a private company" at no cost to the taxpayer. But the core issue here is not that the scheme is overwhelmingly dependent on public subsidy. It is whether that money could have been better spent.

Transport for London has just published its latest annual Travel in London report (pdf), which, on page 121, considers the rate of progress towards "increasing the number of cycle journeys in London by 400 per cent between 2001 and 2026." It notes (page 121) a "substantial increase" in the number of journeys by bicycle since 2001 but says:

Despite the significant investment in cycling and the large increases seen in the number of cycling trips more work is required to meet the target...Safety is a concern, both in terms of the safety of the bicycle from crime and also personal safety while cycling.

The report also acknowledges (page 130) "the increase in cyclist casualties on the roads," saying that this reflects the increase in "cycling levels." The London Cycling Campaign thinks the data more alarming:

Sadly the rise in the number of cyclists has been accompanied by a disproportionate number of injuries involving bicycles - the number of injuries and fatalities grew by 22%, more than four times the 5.2% increase in the number of people cycling.

This prompts me to recall an earlier piece of TfL research (pdf) which found that while committed cyclists were cycling more, but that many new cyclists in London were quickly deterred by anxieties about safety. It is potential new cyclists that London most needs to encourage.

Some of these safety concerns might be addressed in the mayor's plans to improve the road network, and it's significant that Cyclists in the City is impressed by TfL's plans to improve the notorious Bow roundabout junction. Maybe things are looking up. But maybe too the £225m that will soon have been sunk into the cycle hire scheme would have been better spent on simply making the roads safer to cycle on.