Most of us tend to consider the headrest as one of the more comfortable parts of a car. We use it on long journeys to support our heads, lean back against it at a traffic light, or rest while someone else is driving. What may not come to mind is that this padded support is also a closely regulated safety feature. The National Highway Traffic Safety Administration's laboratory test procedure for head restraints, TP-202aS-01, specifies a maximum backset of 55 mm for front outboard restraints, referring to the distance between the back of the head and the front surface of the restraint. The same procedure sets requirements for height, energy absorption and structural strength.
Why the gap behind your head is more important than a cushion
