Lots of red tape and statistics collected before they ever reshape a road, just as many proposed changes fail as those that happen.
Some of the biggest cycle safe changes have been removing railings and making good the curb/pavement as they take them out. I remember watching the process outside my house from people standing about counting traffic to planning notices going up to the railings being pulled down. Being able to jump to the safety of the pavement as my bike is crushed instead of being crushed with it isn't my first choice of things to do but I never say never.
Another thing is putting in millions of really crappy advanced stop boxes for cyclists, I have ranted on here before but they are the most useless and ignored things ever. I often think "it's amber so I should stop, the car behind me is going to jump the lights at the last second so I will die in that box if I slam the brakes on now". I'm sure in a perfect world they might work but the truth about it is they are just rubbish, the retro fitted ones more so as you then often can't see the lights if you are at the front of the badly added advanced stop box. A handful work well, mostly the ones on the cycle super highways but I could talk for days about the ones implemented badly. Another golden one is where the road is too narrow for a cyclist and a car side by side so the filler path for the cyclist is mid lane and always covered by a car(so much fail).
Some of the routes are amazingly well planned and work really well, the routes around elephant and castle to avoid the horid roundabout is one I can't thank tfl enough for but I often turn off to follow the little blue signs and see others zoom into the mess that is elephant and castle.
Free maps/cycle maps if you need/want them. I almost always carry map 14 in my bag, has helped many times when roads have been closed or I have gotten a phone call to say change direction/route with little warning and the first route that springs to mind isn't one I like.
https://www.tfl.gov.uk/roadusers/cycling/11682.aspx
I think the news are enjoying stirring the pot with the "just some blue lines" comment, the vast majority of motorists try to avoid driving on the blue/green lines and the ones who don't you simply don't pass unless it's safe to do so. Similar stuff like putting up a "beware speed cameras" sign without a speed camera can reduce speeding on roads.