A standard riposte one hears to limiting signage, signals, etc. for aesthetic or other reasons; or for executing non-standard traffic treatments (I'm looking at a photo in Texas of a tree planted smack dab in the middle of a residential street; 'natural traffic calming' I suppose!) is that the city will be sued, etc., by drivers who get into crashes as some result of the treatment.
Has anyone seen a study that discusses the actual number of cases of successful lawsuits, or even the frequency with which this actually happens? Is it a bogeyman, or a real fear? I've seen studies, for example, that say that railroad crossings with 'good' sight distance have as many car/train collisions as those with 'poor sight distance -- but does having the proper distance at least absolve the city in case of a crash?
Perhaps this has been discussed here before, but I couldn't find the thread -- in any case, be curious to see papers, hear examples, etc.