Two recent events in London give a good example of what works for increasing the level of cycling and what does not.
First,
Cycle Fridays. This is an attempt to get Londoners to cycle to work by accompanying them on the roads. On Fridays it's possible to ride with other commuters through the traffic to get to work. Six different routes to four destinations are on offer. On the best day so far, this attracted just 88 people shared between the six routes.
Second, the
London Sky Ride. This involved closing 15 km of streets to provide a car free experience. 50000 people took part. That's still only 0.6% of the London population, but it's orders of magnitude more than were tempted by Cycle Fridays.
I've said it before, and no doubt I'll say it again. If you want to see mass cycling, the experience has to be
pleasant,
safe and
convenient. Riding in London traffic doesn't score very highly for any of these things, which is why it was less popular than "Sky Ride" which at least achieved two of them.
In attempting to grow cycling, Britain seems willing to try almost anything other than the only thing that actually works - which is... building proper infrastructure for cycling.

London has made a lot of bold claims, but when you
look at the details on the TFL website you find that their idea of a "cycling superhighway" is a strip of blue tarmac on the road as shown to the left (they've since removed this photo and put on some others which are equally unconvincing). They're not exactly aiming high. Even the artist's impression shows a bus in the cycle lane. This ought to be the "before" photo of a set of "before" and "after" photos, not what is being aimed at. It's really not remotely enough to attract mass cycling.

Perhaps London ought to aim for something a bit more like this, which is not an artist's impression but something retrofitted to a few km of streets in Assen a couple of years ago. Get people away from the cars and they're more likely to be attracted to cycling.

Oh, and it's a good idea to make sure that bus stops are more
like this, so that buses don't cut across cyclists. Buses and cyclists can
co-exist very well, but not in the same lanes.
Neither of these are described as superhighways, of course. They're simply efficient city cycle paths. Junctions on them have been
shown previously.

The Netherlands also has "superhighways". They're called "
fietssnelwegen" and tend to look a bit like what you see to the right. The idea of these is to provide a network of
fast inter-city routes right across the country, and they've been quite successful in drawing people from cars. It has been shown that
building them is cheaper than not building them. The photo came from
here.
I have a similar path, though a bit further from the motorway,
on my commute. I stop once in 30 km.
Another thing London needs to address is that they are simply not aiming to put the routes close enough together for them to be effective. This was researched by the Dutch
back in the 1970s, results were published. Successful policies have been followed ever since, leading to the highest cycling rates in the world. Why try to re-invent the wheel ? And why do so badly ?
I noticed something else very odd about the fake photo from London. The cyclist is scaled down relative to everything else and is no taller than the gray car which is about the same distance away. This gives the impression that the cycle lane is wider than it is.
And another thing. I've had a few people say that London adding cycle lanes is a good thing and that I shouldn't be complaining about it. Here's the explanation: Yes, adding cycle lanes is a good thing. However, if they're going to describe them as "superhighways" then a bit more effort is called for. Compare what's on offer with a mere
"cycleroute+" in the Netherlands.
Update 11/10/2009: London has produced a video display which works by pedalling an exercise bicycle so you can see how the "superhighway" will look. It
doesn't look particularly impressive.

9/11/2009: TFL changed their website to get rid of the "artists impression" above, replacing it with the super cheesy "supercyclehighway-man" seen on the left.
In other news, the "superhighway" is now revealed to be a 1.5 m wide cycle lane on the road, with the only unique feature being blue paint. Given that the minimum recommended width for an on road cycle lane in the UK was already 1.5 m, with 2 m being recommended in areas with more motor traffic, this doesn't sound all that "super"
What's more, the standards where we live now call for single direction cycle paths to be a minimum 2.5 m wide, and bidirectional paths to be 4 m wide. They are separated from the road by a minimum of 1.5 m. That's the measure of a "cycle path" here, without the hyperbole of calling it a "super" anything.
Finally, to see more about cycling "superhighways" in the Netherlands on a completely different scale to what is being planned in London, look at the other posts
tagged with superhighways.
For more on the London "superhighways", click here. Don't worry that decent infrastructure costs too much. It's cheaper to invest in it than not to. Even the benefits to employers add up to rather more than is spent. So go on, London, do a proper job !