@chdot
If Edinburgh is serious about making cycling safe, we need signs like that Prague one. And also signs like the Spanish and French ones I posted links to the other days.
They're a necessary complement to the work Dom is doing. (And Dom's work would be a necessary complement to those signs.)
If this is an education process - which is fair, because for decades, drivers have been taught the wrong "rules" - then posters/signs are a way of getting that information across to the masses in a very low cost way.
(Clearly the council believes this, otherwise they wouldn't have put up all those signs about 20mph limits - e.g. the one outside Leith library.)
And, speaking from someone who has studied behavioural economics (to some extent), you tend to need:
(A) Clear specific rules they can follow. Tell them 1.5m, not "don't drive too close."
(B) A reason why.
(C) And attach it to something positive ("I overtake considerately 1.5 M for your safety.") so people don't feel they're being forced to comply, but instead, are doing something they agree with.
i.e. "I'm a considerate person, so I'm going to do this."