The number of automobile collisions in Macropolis is increasing because of a substantial increase in the sale of new automobiles, and thus an increase in vehicles on the roads  Many of the fatalities that occur in such collisions are caused not by the collision itself, but by an inherent flaw in the locking mechanism within the doors of most new automobiles produced in Macropolis  For example, upon impact, the door locks jam, impeding escape
Ttherefore, to reduce the total number of fatalities that result annually from such collisions in Macropolis, the local automobile factory should be required to redesign the locking mechanisms in its cars
The number of deaths that occurred in prison fires because prisoners could not escape was greatly reduced when prisons were required to rewire any electronic lock that was connected to their fire alarm system.