Yesterday, the city sent out a press release showing that the Stone Way “road diet” has improved safety on the street. The so-called diet converted the north Seattle street from a four lane road into one that has two lanes, a center turn lane, and bicycle lanes. Publicola summarizes the press release:
• The percentage of drivers exceeding the 30 mph speed limit on Stone Way by 10 mph or more dropped about 75 percent—from about 4 percent to about 1 percent. A pedestrian struck at 20 mph, according to studies cited in SDOT’s report, has an 85 percent chance of survival, compared to only 15 percent for a pedestrian struck at [a higher speed].
• While car traffic on Stone Way decreased 6 percent after the road was rechannelized, bike traffic increased a whopping 35 percent, with bike traffic representing around 15 percent of rush-hour trips on the road.
• Traffic on neighborhood streets did not increase, as some neighborhood residents feared; instead, it actually declined substantially, with traffic volumes as much as 49 percent lower on streets parallel to Stone Way. Only two parallel street segments showed any increase—one, Woodland Park Ave. N. at N. 42nd St., climbing by 2 percent (three cars) at morning rush hour, and the other, Woodland Park Ave. N. at N. 50th St., increasing by 27 percent (12 cars) at morning rush hour.
• Collisions between cars and cars, bikes, and pedestrians declined dramatically—14 percent—after the new bike lane and sharrow were introduced. And collisions causing injuries fell even further—33 percent. Finally, car collisions with pedestrians declined even more dramatically —fully 80 percent.
Notably, while local businesses predicted endless traffic on the corridor, the city says that “volumes show the roadway still easily accommodates motor vehicle traffic.”