SellYouOnAnything

So I am to understand you would implement a terminator traffic cop system on public roads? Someone contact the government, this man needs a grant.

Two questions:

1. What kind of social manipulations would you want to implement on highways and roads to speed up traffic, but can't because its impractical/annoying/unethical?

2. Help me settle a dispute. Traffic heading four directions meets at an roundabout. Each in-road is two lanes, one for each direction. There are stop signs at each road. Is that how its supposed to work? Whats the deal with the stop signs?