Not as simple as you might think this one.
I'm always tempted on to the off-road cycle path heading out of Cambridge there. Nasty roundabout to cycle, because its full of angry motorists coming too fast because they've just been wasting their lives on the A14 (if you know these junctions of the A14 skirting the North of Cambridge you'll understand). But that bits quite good, the off-road route around the roundabout is pretty much okay. But its what comes next that is the problem.
Look closely at where the off-road facility ends; it suddenly becomes a cycle lane, you're dropped from the pavement level down on to the road. Decent enough slope down, but heres where the problems start:
http://tinyurl.com/2rwfh6
See that you're now in a cycle lane that ain't really as wide as you'd want, and more importantly you've got traffic moving at a decent pace on your right, making the business of claiming primary before the corner (the one I think the original poster was referring to) rather more difficult than you'd hope.
Of course, while bombing down the slope from the roundabout you CAN keep an eye over your shoulder and hop down on to the road earlier, but the cars coming down from there are going frightfully fast and most of the regular motorists get one hell of a shock to see a cyclist doing that. So yeah, arguably better, but still not ideal.
The problem here is really one of a very badly implemented cycle 'facility', coupled with a road thats frequently completely saturated with traffic.
How to avoid that left hook... Gosh, I rekon that the best approach would be to brazen it out on the road as soon as you can from when you're over the roundabout, from a wee bit further down the road I'd say claim primary. But in all honesty thats not how I ride that road, and I'm an assertive primary rider whenever I can be. I'd have been at risk from that left hook too.
