Fewer than a quarter of the total number of chases during that period were terminated because the danger to citizens and officers was too high or the offense did not warrant the risk.
During those years, 24 residents were hurt by incidents that happened during pursuits; only one police officer was injured.
It's not a perfect record, and no amount of practice could ever make it so. But they try, Cornman said.
Officers hone their skills on a closed course, where they practice evasive driving, braking maneuvers, pursuits, and weaving through obstacles in drive and in reverse.
The strategy police officers use to maintain strict control while driving is called “shuffle steering,” whereby they always keep their right hands on the right side of the wheel and the left on the left side — pushing the steering wheel rather than pulling it.
During a pursuit, officers have to contend not only with the actions of the fleeing driver, but other drivers on the road, pedestrians crossing the street, the weather and condition of the roads, all while they're doing their best to keep their wheels on the road.
Officers also broadcast a detailed and constant description of the driver's actions over the radio during the course of the pursuit. This allows patrol supervisors listening to determine whether or not to end the chase if it becomes a safety risk. This audio record also is imperative for the successful prosecution of crimes committed on the roads.
During another aspect of pursuit training, a veteran police officer takes the helm of a “violator” car. A traffic stop is initiated as it would be on the road, and the violator flees, leading police on a pursuit around the course, which requires officers to use all of the previous skills they've practiced while constantly updating police headquarters on the fleeing driver's actions.
The officers pursue in pairs, with a primary officer — or the officer directly behind the offending vehicle — and one tailing him. The cars swap positions after two laps.
The decision to pursue is evaluated throughout, and the primary officer in a pursuit retains the right to cancel the chase at any time if they deem the risk to be too high.