Some of those problems are down to the specifics of the track, but some are inherent (I made clear that both types of problem existed - although I didn't seperate the problems for the most). I will grant you that I can't provide first hand experience of using a particularly well designed track because there aren't any in London. But I still don't think they're nearly as good as using the road properly.
Here are some of the problems I listed above I believe to be inherent to any such facility. Feel free to explain to me how they're not:
- Plenty of conflicts with cars where the traffic doesn't respect the priority (either through malicousness or incompetence (given the gutter on the wrong side of the road is not where they'd naturally expect a cyclist to be)) and cyclists don't look - Unless you meticulously traffic light or turn restrict every junction and have a crossbow armed red light enforcer stood by the cycle track (or consider those who jump lights collateral damage, but I hardly think that's fair on the drivers who may hit them) there is no escaping this problem.
- Cyclists nearly getting hit as they try and merge with the traffic at the start/end of the lane - Merging with moving traffic isn't easy at the best of times but every lane must have a start and an end. What other solution is there?
- Pedestrians jumping out in front of you - you could put up fences I guess... :P
- Vans parked in it; vans stopped across it in the process of pulling out of a driveway - Silly me, what was I thinking? Residents don't deserve access to their driveways!
- bizarre lhs-rhs switch half way down (you can't blame the engineers for this one though; it's about the only way to effectively end the darned path) - This is possibly specific to the junction layout at that particular junction but I can't see how you could have a segregated facility there any other way. (I can't really see how you could solve this problem without "over engineering" - even at other junctions, anyway.)
- Drivers driving agressivly towards those cyclists that choose not to use it - There are many reasons (often navigational) why you may not to use even a hypothetically perfect segregated facility. But the taxis don't care, cyclists should be in cycle lanes or, if they're not there, the gutter is their philosophy.
- I wanted to turn right but I can't because I'm on the wrong bleeding side of the road - Proabably my number one issue with these things. Often this renders them next to useless for some journeys. Of course I could just pull across a lane of oncoming cyclists, a raised curb and two lanes of dense moving traffic. Or I could just not use it. It's a problem even when it's not on the "wrong" side of the road because you still have to pull more or less the same maneauver.
- and for car drivers - They now have to take a long and contorted route. Annoying them. Making them annoyed at cyclists. And causing them to drive more miles thus poluting more and proving more opportunities for them to hit a cyclist. Way to shoot yourself in the foot :s
That's assuming cyclists use the facilities 100% correctly and the facilities don't encourage dangerous cycling (either on the facilities themselves; or by people attempting to replicate moves allowed by the facilities in locations where there are no facilities).
Yes, that track could be improved; particularly by widening. And yes, that particular road could easily loose a traffic because it is near and parrallel to the Euston road. That certainly does not apply to all of Londons roads, though, and it certainly won't eliminate all the issues with it.
That royal collage street cycle path is also horrendous. I mean, seriously, did nobody spot that the bus stops would get in the way? Also lack of obviously marked priorities on the bus stops (iirc, at least - he incorrectly (https://maps.google.co.uk/maps?q=royal+college+street&hl=en&ll=51.539289,-0.135956&spn=0.01743,0.045447&sll=52.8382,-2.327815&sspn=9.031557,23.269043&hnear=Royal+College+St,+London+NW1+0SG,+United+Kingdom&t=m&z=15&layer=c&cbll=51.538879,-0.135895&panoid=skCT70y3LvgtzmldjcLrDw&cbp=12,181.8,,0,20.06) states there are give way lines) leads to a situation where I believe the cycle track technicaly retains priority - but you have to be a maniac fool to actually take that priority because you'd probably end up hitting someone (they should have zebra stripes painted on them, or something, to make clear that cyclists should give way). And, of course, all London's buses only have doors only on the LHS. So this is going to be an issue whenever you build a cycle track down a two way road a bus route follows - or on the LHS of a one way street with buses. I know he says much of the above - but I don't think that would be good nor safe; just less bad and less dangerous than as current.