Contrary to the saying, experience is not the best teacher for driving. Poor driving habits or improper formal or informal driving instruction carries on through years of driving unless the driver is retrained and can cause, rather than prevent, accidents. After alcohol use, the two most significant causes of accidents analyzed by the Traffic Safety Department at General Motors' Milford Proving Grounds were misinterpretation of the driving task and improper vehicle control in emergency situations. The Department developed and tested a driving course consisting of six driving exercises addressing one or more of the common causes of accidents: skids, improper evasive maneuvers, improper off-road recovery, and improper braking. Its training for law enforcement instructors focuses on performance rather than pursuit driving. The 2-day training program includes classroom and driving time. As a result of this training, the trained police officers from the sheriff's department of Oakland County (Mich.) had an average cost per accident of $289 and no lost time compared to averages of $1,446.50 and 87 days lost for the untrained group.