James Reason's classic book Managing the Risks of Organizational Accidents has a lot of great risk management insights. Here are three paragraphs on adding too many procedures over time (p. 49):
All organizations suffer a tension between the natural variability of human behaviour and the system's needs for a high degree of regularity in the activities of its members. The managers of hazardous systems must try to restrict human actions to pathways that are not only efficient and productive, but also safe. The most widely used means to achieve both goals are written procedures. But there are a number of important differences between the procedures for production and those for protection.
Although by no means immutable, the procedures designed to ensure efficient working tend to arise fairly naturally from the nature of the productive equipment and the task to which it is put. Safe operating procedures, on the other hand, are continually being amended to prohibit actions that have been implicated in some recent accident or incident. Over time, these additions to the 'rule book' become increasingly restrictive, often reducing the range of permitted actions to far less than those necessary to get the job done under anything but optimal conditions.
Figure 3.1 illustrates this shrinkage of allowable action as it occurs over the history of a given system. This could be a chemical process plant, a railway, an aircraft operating company - or any hazardous technology at risk to organizational accidents. The space between the shaded areas represents the scope of prescribed action. As time passes, the organization inevitably suffers accidents and incidents in which human actions are identified as contributing factors. After each event, the procedures are modified so as to proscribe these implicated actions. As a consequence, the scope of allowable actions gradually shrinks to a range that is less than that required to perform all the necessary tasks. The only way to do these jobs is to violate the procedures.
These are just three paragraphs of condensed juicy safety wisdom. I encourage you to pick up a copy and read the rest. It's just as good.