Chief Jeff Hadley said he attributes the drop since September 2013 to the study, which has led to changes in patrol philosophy and strategies. Hadley said effectiveness shouldn't be measured by the number of stops.
"The traffic stop is a tool that we have in our toolbox. But is this the best way to approach crime in our city?" Hadley said. "To go out in any neighborhood and make an abundant number of traffic stops in an effort to find drugs or weapons, we have rethought that idea."
Kalamazoo Department of Public Safety officers made 3,841 stops between September and January, compared with 7,298 from September 2012 to January 2013.
Hadley said in September that he planned to use the study's recommendations to make changes. The study also found that black motorists were given fewer citations yet were more likely than whites to be asked to exit their vehicles and to be searched, handcuffed and arrested.
Since then, Hadley said the department is focusing more on directed patrols where officers target a neighborhood or area that is experiencing high levels of crime or traffic problems. Directed patrols increased to 7,060 between September and January from 5,072 for that period a year earlier.
The department, meanwhile, this month is implementing a policy for when officers can search drivers or cars following stops.
The study was done at the request of the city's Citizens Public Safety Review and Appeals board. It was a voluntary move, but there had been past complaints. About 22 percent of Kalamazoo's residents are black, according to figures from the U.S. Census Bureau.