Wired magazine has a good article on the latest thinking in traffic engineering: build roads that seem dangerous and they'll actually be safer. Think of it this way: the less contextual cues and more direct signage and markings you used to direct traffic, the less drivers will think about their choices and actions when they drive. Use less signage and require drivers to slow down just a bit and read the context of the situation and they will drive more intelligently and carefully. Experiments and studies so far have shown this to be true.

Most of the work and implementation in this area has gone on in Europe, but many people in the US are taking notice. Think of how many intersections or situations in the US you have driven through where you have gone into road sign and road marking overload - in many places putting in more signs just adds to the confusion and decreases safety.