Risk compensating behaviour[0] is a real thing; the question is whether that effect is significant in any particular case. Making the roads look less safe will make people drive more carefully, but it has to be shown whether this will cause a net decrease of actual crash rate.
> Making the roads look less safe will make people drive more carefully, but it has to be shown whether this will cause a net decrease of actual crash rate.
There is also the matter that many of the ways to make roads look less safe would in actual fact make the roads less safe. At a given speed, narrower lanes increase the probability of a collision. Parked cars on the side of a road increase the probability that one will be hit, or conceal from motorists the presence of pedestrians about to step into the street.
People focused on speed are asking the wrong question. The question is not "how do we get people to slow down" but rather "how do we make the roads safer"? Speed is only one variable.
[0] - http://en.wikipedia.org/wiki/Risk_compensation