Having the car slip or roll off of the jack can be extremely dangerous to yourself and others. To prevent this, always work on a flat surface away from moving vehicles or distractions. The surface you work on should be hard and sturdy so that it will not shift or give way while you are working. A concrete driveway or garage away from the road are good examples. A yard is a bad choice — even if it's flat, the dirt may not be strong enough to support the car. As noted above, the instructions in this section are intended to protect yourself and others in the event the car slips off its jack. If you can't meet the conditions above but you absolutely must jack up the car, use the instructions below to make the process safer:  If you must jack the car on a soft or broken surface such as a dirt shoulder, use a thick, flat piece of wood to make a stable platform for the jack. If you must jack the car on a slight incline, park next to the curb and turn the wheels into the curb so that they are touching it. This will prevent an out-of-control car from hurting others if it slips off the jack. Similarly, if you don't have anything to block the wheels with, turn the tires into the curb.  Never jack the car on the shoulder of a roadway. If you must jack the car somewhere near traffic, put on your hazard lights. If you have flares, cones, or pylons, use these to direct traffic away from you.
اركن السيارة على سطح مستوٍ وصلب. اتخذ احتياطيات إضافية في الظروف السيئة.