the real problem is this: segregation makes cycling another, subsidiary problem instead of part of the answer. The correct way to rid our streets of congestion, reduce road deaths, reduce traffic generated fumes and noise is to reconfigure them as social spaces, in which pedestrians, cyclists (including cycle cabs), buses, delivery vehicles get people and goods around. It works when it's tried - and it's good for business. The correct response to congestion is to reduce trip generation.
But....the government promotes out of town housing development, and refuses absolutely to close all but a few high streets to the car - on the grounds that they are mostly A roads. Sustrans is a neat cover for this - all those scratchy little lines weaving around and about, crossing paths, bunnyhopping kerbs tell councils and the government that 'something is being done'. So...spend a wodge of money on a path to circumvent the Mile End Road, neglecting the fact that the Mile End Road is one of the most well cycled roads in London (whoops!) and that the crying need is to make the Mile End Road a nice place to be - the kind of place that you can call the centre of your town, rather the road to Stratford or a feeder road for the Blackwall Tunnel.
I don't think that Sustrans does a great deal of harm. But that's it. And, despite the gloom of the paragraph above it does seem that the Government is getting the message about cycle paths. Central funds are going in to training and (dread phrase) 'modal shift'. My MP - an ex-Minister for cycling - said that he's signed orders for tens of millions of pounds worth of cycle paths and he wasn't convinced that they were doing a bit of good. The London/outside of London split (cycling rising exponentially/cycling flat) is pretty obvious. GOAL 2012 went south and Sustrans lottery bid is really a bit desperate. I won't be voting for it, but then I won't be voting for anything - I detest the wretched lottery.