@Snowy: spot on analysis.
The only thing I would add is the appetite to make such a change. I'm not sure that would be a battle we could win. Locals, though traffic & the potential development of David Murray's Garden District would all have been against us.
@Tulyar: Summary - it's significant improvement to a stretch of road that's been hostile to cycle on for years = A lot of love for it.
It's been 10 years since a Global HQ was built nearby, which increased traffic in its own right and built a bridge over the A8 which allowed Westbound A8 traffic to access GSR and added to the traffic.
Since then it's not been a pleasant road to cycle on. It was the source of regular grumbles amongst the cyclists that used it with tales of close passes and driver aggression. There was some engagement with the council but not enough to turn the dial - the problem being that you would only get short snippets of conversation as people came & went in the changing room.
3 years ago someone (who's on here) set up a Bicycle User Group at work, which similar to CCE allowed for the joining up of ideas and grumbles so that pressure can be exerted to fix them.
After some good success with onsite issues, the problem of GSR was agreed to be tackled and there started a concerted campaign to persuade CEC to act. A lot of emails have been written by a lot people.
Those who have used it are genuinely pleased that we don't have to dodge the potholes anymore, which in winter was particularly scary. Hopefully the close passes & speeds should reduce too.
It is a relief that with the exception of a nasty road rage incident last year, we have managed to get through the last few years without a serious incident caused by the state of the road.
The celebration is a chance to recognise the improvement is welcomed by those that use it. Yes, it could be better but at least we aren't still waiting for it.
A bit of PR for this sort of thing won't go a miss both to persuade CEC (& other LAs) to do more like it but also reinforce the message that close passes are dangerous and unacceptable.