At speeds below 35 MPH, it can be used on a fleeing vehicle, if the legal parameters would justify "less than lethal force" against the driver. At speeds greater than 35 MPH, the technique still works, but it is considered potentially lethal and normally would only be used if lethal force is justified against all occupants. It is best used when the driver is on surface streets and cornering. A high speed motorist may kill innocent people and it can sometimes be justified for that traffic offense. Since there may be unwilling or innocent passengers in the car, there is an inherent difficulty in justifying the use of PITs.