An anonymous reader writes "They're the holy grail of transportation engineering: streets and highways specifically designed to encourage automobilists to drive less quickly, reducing the rates of passenger fatalities and generally encouraging a safer urban environment. And now new research shows that, if built right, they just might work. A new study out of the University of Connecticut suggests that minor reductions in vehicle speed are possible through changes in the street environment. Through the use of roadside parking, tighter building setbacks, and more commercial land uses, road designers can make drivers subconsciously drive more slowly." All of that is gonna work a lot better than my strategy of placing car-sized holes covered with twigs and branches randomly every half mile or so down the interstates.