The study looked at "road diets" in several cities and suburbs in California and Washington, including Bellevue and Seattle. It also analyzed data from small towns in Iowa. The study looked at four-lane rechannelized similar to the city's proposal for Northeast 125th Street in North Seattle and other recent lane reductions on Stone Way North and Nickerson Street in which the fourth lane was converted to another use such as bike lanes or sidewalks.
The data from Washington and California showed a 19 percent reduction in collisions. The data from Iowa showed a 47 percent decrease.
Urban road dieting
I think that some of the options for "road dieting" are different in traditional center cities, which often don't have the wide traffic sewers that we may typically associate with suburban driving conditions, but still prioritize the movement of motor vehicles over walking, bicycling, and transit in many ways, sometimes without realizing it.