A constant concern for those involved with operating fly systems is the possibility of an unbalanced line set that results in a runaway. A runaway is a physical hazard to the people working on the stage. It is also a psychological hazard to the supervisors of the work. The prevention of a runaway is a great source of stress for stage carpenters and technical directors. Many TD’s have said that they ‘lose sleep’ the night before a load in or out. The major method of preventing runaways so far has been procedure. Although necessary, procedure is not the preferred method of hazard mitigation. Stress is significantly reduced with arbor traps installed because, when used, the arbor trap eliminates the possibility of a runaway. It is stage carpenters and TD’s that, when shown the trap, immediately want it.